[cmake] Pass LLVM_TABLEGEN_FLAGS to cross compile targets

If ValueTypes.td contains conditional directives enabled by defs
in LLVM_TABLEGEN_FLAGS then native build tblgen and min-tblgen
must be built with matching flags.
This ensures the embedded types in TableGen are consistent with
those used for building tables.

Author: perlfu

llvm/cmake/modules/CrossCompile.cmake

@@ -100,6 +100,7 @@ function(llvm_create_cross_target project_name target_name toolchain buildtype)
         -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN="${LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN}"
         -DLLVM_INCLUDE_BENCHMARKS=OFF
         -DLLVM_INCLUDE_TESTS=OFF
+        -DLLVM_TABLEGEN_FLAGS="{LLVM_TABLEGEN_FLAGS}"
         ${build_type_flags} ${linker_flag} ${external_clang_dir} ${libc_flags}
         ${ARGN}
     WORKING_DIRECTORY ${${project_name}_${target_name}_BUILD}