PowerPC64 pcrel got relocs against local symbols

PowerPC64 pcrel got relocs against local symbols

Not that anyone would want to indirect via the GOT when an address can
be loaded directly with pla, the following:

 pld 3,x@got@pcrel
x:

leads to "Internal error in md_apply_fix", because the generic parts
of assembler fixup handling convert the fx_pcrel fixup to one without
a symbol.  Stop that happening.

	* config/tc-ppc.c (ppc_force_relocation): Add PLT_PCREL34 and
	assorted GOT_PCREL34 relocs.