Unify lookup_symbol_in_objfile_symtabs

Unify lookup_symbol_in_objfile_symtabs

That's right, block_lookup_symbol_primary()'s additional requirement over
block_lookup_symbol() is:
	Function is useful if one iterates all global/static blocks of an
	objfile.

Which is satisfied both in lookup_symbol_in_objfile_symtabs() and in
lookup_global_symbol_from_objfile() thanks to their's ALL_OBJFILE_COMPUNITS.

In fact after reverting that ba715d7fe49c8a59660fbd571b935b29eb7cfbdb above
the lines of code were exactly the same.

So instead of accelerating both lookup_symbol_in_objfile_symtabs() and
lookup_global_symbol_from_objfile() I just accelerated
lookup_symbol_in_objfile_symtabs() and I am proposing to reuse
lookup_symbol_in_objfile_symtabs() in lookup_global_symbol_from_objfile()
instead.  In fact such unification would already save some lines of code even
before the checked-in acceleration patch above.

gdb/ChangeLog
2014-12-05  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* symtab.c (lookup_symbol_in_objfile_symtabs): New declaration.
	(lookup_global_symbol_from_objfile): Call it.