Also remove the 'rc' suffix from a release candidate.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_28@113532 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/Makefile b/include/clang/Basic/Makefile
index 7db3e29..bc64f6a 100644
--- a/include/clang/Basic/Makefile
+++ b/include/clang/Basic/Makefile
@@ -16,6 +16,7 @@
 # Compute the Clang version from the LLVM version, unless specified explicitly.
 ifndef CLANG_VERSION
 CLANG_VERSION := $(subst svn,,$(LLVMVersion))
+CLANG_VERSION := $(subst rc,,$(CLANG_VERSION))
 endif
 
 CLANG_VERSION_COMPONENTS := $(subst ., ,$(CLANG_VERSION))