[CMake] Cleanup TableGen include flags

It is kinda crazy to have llvm/include and llvm/lib/Target in the include path for every tablegen invocation for every tablegen-like tool.

This patch removes those flags from the tablgen function that is called everywhere by instead creating a variable LLVM_TABLEGEN_FLAGS which is setup in the LLVM source directories.

This removes TableGen.cmake's dependency on LLVM_MAIN_SRC_DIR, and LLVM_MAIN_INCLUDE_DIR.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288770 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed