[lit] Add host_cxx to lit config

Summary: This is required to get the clang version for sanitized builds.

Reviewers: zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38741

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315338 91177308-0d34-0410-b5e6-96231b3b80d8

test/lit.site.cfg.py.in

@@ -14,6 +14,7 @@ config.clang_src_dir = "@CLANG_SOURCE_DIR@"
 config.clang_tools_dir = "@CLANG_TOOLS_DIR@"
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@TARGET_TRIPLE@"
+config.host_cxx = "@CMAKE_CXX_COMPILER@"
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = @HAVE_LIBZ@
 config.clang_arcmt = @CLANG_ENABLE_ARCMT@