sed -i 's/. They/. They/'

Truly editorial fix for comments.  This works better with Emacs'
set-justification-full function. [ci skip]

include/ruby/internal/arithmetic/char.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `char` and Ruby's.
  */
 #include "ruby/internal/arithmetic/int.h"  /* NUM2INT is here, but */

include/ruby/internal/arithmetic/double.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `double` and Ruby's.
  */
 #include "ruby/internal/attr/pure.h"

include/ruby/internal/arithmetic/fixnum.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Handling of integers formerly known as Fixnums.
  */
 #include "ruby/backward/2/limits.h"

include/ruby/internal/arithmetic/gid_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `gid_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/int.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `int` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/intptr_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `intptr_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/long.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `long` and Ruby's.
  *
  * ### Q&A ###

include/ruby/internal/arithmetic/long_long.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `long long` and Ruby's.
  */
 #include "ruby/internal/value.h"

include/ruby/internal/arithmetic/mode_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `mode_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/off_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `off_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/pid_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `pid_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/short.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `short` and Ruby's.
  *
  * Shyouhei  wonders:  why  there  is   no  SHORT2NUM,  given  there  are  both

include/ruby/internal/arithmetic/size_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `size_t` and Ruby's.
  */
 #include "ruby/internal/config.h"

include/ruby/internal/arithmetic/st_data_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `st_data_t` and Ruby's.
  */
 #include "ruby/internal/arithmetic/fixnum.h"

include/ruby/internal/arithmetic/uid_t.h

@@ -17,7 +17,7 @@
  *             recursively included  from extension  libraries written  in C++.
  *             Do not  expect for  instance `__VA_ARGS__` is  always available.
  *             We assume C99  for ruby itself but we don't  assume languages of
- *             extension libraries. They could be written in C++98.
+ *             extension libraries.  They could be written in C++98.
  * @brief      Arithmetic conversion between C's `uid_t` and Ruby's.
  */
 #include "ruby/internal/config.h"