re PR target/67172 (i686-w64-mingw32 dwarf2 bootstrap fails with undefined reference to __EH_FRAME_BEGIN__)

	PR target/67172
	* libgcc2.c (L__main): Undefine __LIBGCC_EH_FRAME_SECTION_NAME__ if
	__MINGW32__ is defined.

From-SVN: r234727