Makefile: Switch Clang Makefiles to always include the top-level Clang Makefile.
 - This eliminates most dependencies on how Clang is installed relative to LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105637 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Makefile b/lib/Sema/Makefile
index 3a5a99a..6e13327 100644
--- a/lib/Sema/Makefile
+++ b/lib/Sema/Makefile
@@ -12,11 +12,11 @@
 #
 ##===----------------------------------------------------------------------===##
 
-LEVEL = ../../../..
+CLANG_LEVEL := ../..
 LIBRARYNAME := clangSema
 BUILD_ARCHIVE = 1
 
 CPP.Flags += -I$(PROJ_SRC_DIR)/../../include -I$(PROJ_OBJ_DIR)/../../include
 
-include $(LEVEL)/Makefile.common
+include $(CLANG_LEVEL)/Makefile