[X86][tablgen] Consider the mnemonic when auto-generating memory folding table

Intuitively, the memory folding pair should have the same mnemonic.

This patch removes
```
{X86::SENDUIPI,X86::VMXON}
```
in the auto-generated table.
And `NotMemoryFoldable` for `TPAUSE` and `CLWB` can be saved.
```
{X86::MOVLHPSrr,X86::MOVHPSrm}
{X86::VMOVLHPSZrr,X86::VMOVHPSZ128rm}
{X86::VMOVLHPSrr,X86::VMOVHPSrm}
```
It seems the three pairs above are mistakenly killed.
But we can add them back manually later.

Reviewed By: Amir

Differential Revision: https://reviews.llvm.org/D122477