Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* elfread.c (elf_symtab_read): Set created_by_gdb for @plt minsym
created by gdb.
* symtab.c (lookup_symbol_in_objfile_from_linkage_name): New function.
(search_symbols): Call it instead of lookup_symbol.
Skip symbols created by gdb. Only scan minsyms if nfiles == 0.
testsuite:
* gdb.base/info-fun.exp: New file.
* gdb.base/info-fun.c: New file.
* gdb.base/info-fun-solib.c: New file.
