PowerPC reloc symbols that shouldn't be adjusted

PowerPC reloc symbols that shouldn't be adjusted

GOT and PLT relocs shouldn't have their symbols replaced with a
section symbol plus added.  Nor should the HIGHA TLS relocations,
which failed to be caught by the range test in ppc_fix_adjustable.

bfd/
	* reloc.c (BFD_RELOC_PPC64_TPREL16_HIGH, BFD_RELOC_PPC64_TPREL16_HIGHA),
	(BFD_RELOC_PPC64_DTPREL16_HIGH, BFD_RELOC_PPC64_DTPREL16_HIGHA):
	Sort before BFD_RELOC_PPC64_DTPREL16_HIGHESTA entry.
gas/
	* config/tc-ppc.c (ppc_fix_adjustable): Exclude all GOT and PLT
	relocs, and VLE sdarel relocs.
	* testsuite/gas/ppc/power4.d: Adjust.