[MC] Restore MCAsmBackend::shouldForceRelocation to false

For IsPCRel fixups, we had the `A->getKind() != MCSymbolRefExpr::VK_None`
condition to force relocations. The condition has then been changed to
`Target.getSpecifier()` (086af836889436baffc71c743c7c8259bad8ed60).

38c3ad36be1facbe6db2dede7e93c0f12fb4e1dc updated
shouldForceRelocation to test `Target.getSpecifier`.
It is not a good fit as many targets with %lo/%hi style specifiers
(SPARC, MIPS, PowerPC, RISC-V) do not force relocations for these
specifiers.

Revert the Target.getSpecifier implementation
(38c3ad36be1facbe6db2dede7e93c0f12fb4e1dc) and update
targets that need it (SystemZAsmBackend/X86AsmBackend) instead.
Targets need customization might define addReloc instead.

Note: The X86AsmBackend implementation is too conservative.
GNU Assembler doesn't emit a relocation for `call local@plt; local`
a3d39316764726ed9fd939550c7781199b1eb77e added missing coverage
for GOT/PLT related relocations.

0 files changed, 0 insertions, 0 deletions