load prelude.rb by builtin features.

The script in prelude.rb was embed in MRI to load it (eval this
script at everyboot).
This commit change the loading process of prelude.rb. MRI doesn't
eval a script, but load from compiled binary with builtin feature.

So that Init_prelude() does not load `prelude.rb` now.

common.mk

@@ -163,7 +163,7 @@ ALLOBJS       = $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(INITOBJS)
 GOLFOBJS      = goruby.$(OBJEXT) golf_prelude.$(OBJEXT)
 
 DEFAULT_PRELUDES = $(GEM_PRELUDE)
-PRELUDE_SCRIPTS = $(srcdir)/prelude.rb $(DEFAULT_PRELUDES)
+PRELUDE_SCRIPTS = $(DEFAULT_PRELUDES)
 GEM_PRELUDE   = $(srcdir)/gem_prelude.rb
 PRELUDES      = {$(srcdir)}prelude.c {$(srcdir)}miniprelude.c
 GOLFPRELUDES  = {$(srcdir)}golf_prelude.c
@@ -1000,6 +1000,7 @@ BUILTIN_RB_SRCS = \
 		$(srcdir)/io.rb \
 		$(srcdir)/pack.rb \
 		$(srcdir)/trace_point.rb \
+		$(srcdir)/prelude.rb \
 		$(empty)
 BUILTIN_RB_INCS = $(BUILTIN_RB_SRCS:.rb=.rbinc)
 
@@ -2231,6 +2232,8 @@ inits.$(OBJEXT): {$(VPATH)}onigmo.h
 inits.$(OBJEXT): {$(VPATH)}oniguruma.h
 inits.$(OBJEXT): {$(VPATH)}st.h
 inits.$(OBJEXT): {$(VPATH)}subst.h
+inits.$(OBJEXT): {$(VPATH)}builtin.h
+inits.$(OBJEXT): {$(VPATH)}prelude.rbinc
 io.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 io.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 io.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -2689,7 +2692,6 @@ prelude.$(OBJEXT): {$(VPATH)}node.h
 prelude.$(OBJEXT): {$(VPATH)}onigmo.h
 prelude.$(OBJEXT): {$(VPATH)}oniguruma.h
 prelude.$(OBJEXT): {$(VPATH)}prelude.c
-prelude.$(OBJEXT): {$(VPATH)}prelude.rb
 prelude.$(OBJEXT): {$(VPATH)}ruby_assert.h
 prelude.$(OBJEXT): {$(VPATH)}ruby_atomic.h
 prelude.$(OBJEXT): {$(VPATH)}st.h

inits.c

@@ -10,6 +10,8 @@
 **********************************************************************/
 
 #include "internal.h"
+#include "builtin.h"
+#include "prelude.rbinc"
 
 #define CALL(n) {void Init_##n(void); Init_##n();}
 
@@ -66,6 +68,7 @@ rb_call_inits(void)
     CALL(vm_stack_canary);
     CALL(gc_stress);
 
+    // enable builtin loading
     CALL(builtin);
 
     CALL(GC);
@@ -73,5 +76,6 @@ rb_call_inits(void)
     CALL(ast);
     CALL(vm_trace);
     CALL(pack);
+    load_prelude();
 }
 #undef CALL

template/prelude.c.tmpl

@@ -38,7 +38,7 @@ class Prelude
     @builtin_count = 0
     @preludes = {}
     @mains = preludes.map do |filename|
-      if prelude = filename.end_with?("prelude.rb")
+      if prelude = filename.end_with?("_prelude.rb")
         @prelude_count += 1
       else
         @builtin_count += 1