ASM_OUTPUT_SECTION_NAME cleanup

[Joern Rennecke]

> While that is decent coverage of object file formats (and targets that
> needed special care), it is not all of them.  Let me know if you run
> into any problems.

While the EH_FRAME_SECTION definition in defaults.h used to depend on
DWARF2_UNWIND_INFO, your definition of EH_FRAME_SECTION_NAME doesn't.
This breaks sh-hms, since now the __main.o part of libgcc.a contains
a reference to __EH_FRAME_BEGIN__, which is not defined anywhere
(sh-hms doesn't use crtstuff).