Document the GDB 7.6.2 release in gdb/ChangeLog

gdb/ChangeLog:

	GDB 7.6.2 released.
Fix --as-needed undefined symbol references from dynamic libraries.

libx.so refers to some_sym, liby.so provides some_sym@some_version
wasn't seen as satisfying the reference.

	* elf64-ppc.c (_bfd_elf_add_default_symbol): Set dynamic_def
	and ref_dynamic_nonweak when chaining together indirect
	symbols.
correct file reference
Use gdb_produce_source

We added a new proc gdb_produce_source recently, and it can be used
more widely in lib/gdb.exp to generate source file.

gdb/testsuite:

2013-12-08  Yao Qi  <yao@codesourcery.com>

	* lib/gdb.exp (support_complex_tests): Use gdb_produce_source.
	(is_elf_target, is_ilp32_target, is_ilp64_target): Likewise.
	(is_64_target, is_amd64_regs_target): Likewise.
	(skip_altivec_tests, skip_vsx_tests, skip_btrace_tests): Likewise.