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/Basic/Makefile b/lib/Basic/Makefile
index 58ac7eb..f36a1bc 100644
--- a/lib/Basic/Makefile
+++ b/lib/Basic/Makefile
@@ -11,7 +11,7 @@
 #
 ##===----------------------------------------------------------------------===##
 
-LEVEL = ../../../..
+CLANG_LEVEL := ../..
 LIBRARYNAME := clangBasic
 BUILD_ARCHIVE = 1
 
@@ -20,7 +20,7 @@
 CPPFLAGS += -DCLANG_VENDOR='"$(CLANG_VENDOR) "'
 endif
 
-include $(LEVEL)/Makefile.common
+include $(CLANG_LEVEL)/Makefile
 
 SVN_REVISION := $(shell $(LLVM_SRC_ROOT)/utils/GetSourceVersion $(PROJ_SRC_DIR)/../..)