Add clang_site_config user variable, so that extra tests (e.g., utils/C++Syntax)
can always find the main clang site config (when invoked via CMake/Makefiles, at
least).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86139 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a83a199..8b3c738 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -45,6 +45,7 @@
                   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
       COMMAND ${PYTHON_EXECUTABLE}
                   ${LLVM_SOURCE_DIR}/utils/lit/lit.py
+                  --param clang_site_config=${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
                   -sv ${CLANG_TEST_EXTRA_ARGS}
                   ${CMAKE_CURRENT_BINARY_DIR}/${testdir}
                   DEPENDS clang clang-cc index-test c-index-test
@@ -63,6 +64,7 @@
                 ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
     COMMAND ${PYTHON_EXECUTABLE}
                 ${LLVM_SOURCE_DIR}/utils/lit/lit.py
+                --param clang_site_config=${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
                 -sv ${CLANG_TEST_EXTRA_ARGS}
                 ${CMAKE_CURRENT_BINARY_DIR}
                 DEPENDS clang clang-cc index-test c-index-test
@@ -80,6 +82,7 @@
                 ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
     COMMAND ${PYTHON_EXECUTABLE}
                 ${LLVM_SOURCE_DIR}/utils/lit/lit.py
+                --param clang_site_config=${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
                 -sv ${CLANG_TEST_EXTRA_ARGS}
                 ${CMAKE_CURRENT_SOURCE_DIR}/../utils/C++Tests
                 DEPENDS clang clang-cc index-test c-index-test