make MSYMBOL_VALUE_ADDRESS an rvalue

make MSYMBOL_VALUE_ADDRESS an rvalue

This changes MSYMBOL_VALUE_ADDRESS to be an rvalue.  In a later patch
we change this macro to compute its value; this patch introduces a
setter to make the break a bit cleaner.

2014-02-26  Tom Tromey  <tromey@redhat.com>

	* minsyms.c (prim_record_minimal_symbol_full): Use
	SET_MSYMBOL_VALUE_ADDRESS.
	* objfiles.c (objfile_relocate1): Use SET_MSYMBOL_VALUE_ADDRESS.
	* sh64-tdep.c (sh64_elf_make_msymbol_special): Use
	SET_MSYMBOL_VALUE_ADDRESS.
	* symtab.h (MSYMBOL_VALUE_ADDRESS): Expand to an rvalue.
	(SET_MSYMBOL_VALUE_ADDRESS): New macro.