Fixes the generation of dwarf line debug information for the msp430, even in the...

Fixes the generation of dwarf line debug information for the msp430, even in the presence of function sections and linker garbage collection.

	PR 17940
	* dwarf2dbg.c (out_header): When generating dwarf sections use
	real symbols not temps for the start and end symbols.
	* config/tc-msp430.h (TC_FORCE_RELOCATION_SUB_SAME): Also prevent
	adjustments to relocations in debug sections.
	(TC_LINKRELAX_FIXUP): Likewise.

	* elf32-msp430.c (msp430_elf_relax_delete_bytes): Adjust debug
	symbols at end of sections.  Adjust function sizes.