[X86] Adding new LLVM TableGen backend that generates the X86 backend memory folding tables.

X86 backend holds huge tables in order to map between the register and memory forms of each instruction.
This TableGen Backend automatically generated all these tables with the appropriate flags for each entry.

Differential Revision: https://reviews.llvm.org/D32684



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304088 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed