Reland "[Clang][LoongArch] Add inline asm support for constraints k/m/ZB/ZC"

Reference: https://gcc.gnu.org/onlinedocs/gccint/Machine-Constraints.html

k: A memory operand whose address is formed by a base register and
(optionally scaled) index register.

m: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as st.w and ld.w.

ZB: An address that is held in a general-purpose register. The offset
is zero.

ZC: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as ll.w and sc.w.

Note:
The INLINEASM SDNode flags in below tests are updated because the new
introduced enum `Constraint_k` is added before `Constraint_m`.
  llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-inline-asm.ll
  llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-inline-asm.ll
  llvm/test/CodeGen/X86/callbr-asm-kill.mir

This patch passes `ninja check-all` on a X86 machine with all official
targets and the LoongArch target enabled.

Differential Revision: https://reviews.llvm.org/D134638