https://gcc.gnu.org/gcc-10/changes.html#c
> * GCC now defaults to `-fno-common`. As a result, global
> variable accesses are more efficient on various targets. In
> C, global variables with multiple tentative definitions now
> result in linker errors. With `-fcommon` such definitions are
> silently merged during linking.
* ext/win32ole/win32ole_error.h: ditto.
* ext/win32ole/win32ole.c(typeinfo_from_ole): raise WIN32OLEQueryInterfaceError in ole_methods.
* ext/win32ole/win32ole_method.c(ole_methods_from_typeinfo): ditto.
M ext/win32ole/win32ole.c
M ext/win32ole/win32ole_error.c
M ext/win32ole/win32ole_error.h
M ext/win32ole/win32ole_method.c
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
