Revert "Make llvm_source_root in llvm-lit relative too."

This reverts commit 6c1a9fb.

Commit causes failures:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/49206

Author: hubert-reinterpretcast

llvm/utils/llvm-lit/CMakeLists.txt

@@ -4,16 +4,12 @@ math(EXPR file_last "${file_len} - 1")
 
 get_llvm_lit_path(LIT_BASE_DIR LIT_FILE_NAME)
 
-set(LLVM_SOURCE_DIR ${LLVM_MAIN_SRC_DIR})
-
 # LLVM_LIT_CONFIG_FILES contains interleaved main config (in the source tree)
 # and site config (in the build tree) pairs. Make them relative to
 # llvm-lit and then convert them to map_config() calls.
 if("${CMAKE_CFG_INTDIR}" STREQUAL ".")
   make_paths_relative(
-    LLVM_LIT_CONFIG_FILES "${LIT_BASE_DIR}" "${LLVM_LIT_CONFIG_FILES}")
-  make_paths_relative(
-    LLVM_SOURCE_DIR "${LIT_BASE_DIR}" "${LLVM_SOURCE_DIR}")
+      LLVM_LIT_CONFIG_FILES "${LIT_BASE_DIR}" "${LLVM_LIT_CONFIG_FILES}")
 endif()
 
 set(LLVM_LIT_CONFIG_MAP "${LLVM_LIT_PATH_FUNCTION}\n")
@@ -27,6 +23,8 @@ if (${file_last} GREATER -1)
   endforeach()
 endif()
 
+set(LLVM_SOURCE_DIR ${LLVM_MAIN_SRC_DIR})
+
 if(NOT "${CMAKE_CFG_INTDIR}" STREQUAL ".")
   foreach(BUILD_MODE ${CMAKE_CONFIGURATION_TYPES})
     string(REPLACE ${CMAKE_CFG_INTDIR} ${BUILD_MODE} bi ${LIT_BASE_DIR})

llvm/utils/llvm-lit/llvm-lit.in

@@ -13,6 +13,12 @@ def map_config(source_dir, site_config):
     site_config = os.path.normpath(site_config)
     config_map[source_dir] = site_config
 
+# Variables configured at build time.
+llvm_source_root = "@LLVM_SOURCE_DIR@"
+
+# Make sure we can find the lit package.
+sys.path.insert(0, os.path.join(llvm_source_root, 'utils', 'lit'))
+
 # Set up some builtin parameters, so that by default the LLVM test suite
 # configuration file knows how to find the object tree.
 builtin_parameters = { 'build_mode' : "@BUILD_MODE@" }
@@ -21,10 +27,6 @@ builtin_parameters = { 'build_mode' : "@BUILD_MODE@" }
 
 builtin_parameters['config_map'] = config_map
 
-# Make sure we can find the lit package.
-llvm_source_root = path("@LLVM_SOURCE_DIR@")
-sys.path.insert(0, os.path.join(llvm_source_root, 'utils', 'lit'))
-
 if __name__=='__main__':
     from lit.main import main
     main(builtin_parameters)