Basic: Tweak attempt to make version tags work from 'svn export's again, clip

off the extra parts of the $URL$ SVN keyword.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116269 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Basic/Version.cpp

@@ -31,8 +31,10 @@ std::string getClangRepositoryPath() {
   // If the SVN_REPOSITORY is empty, try to use the SVN keyword. This helps us
   // pick up a tag in an SVN export, for example.
   static llvm::StringRef SVNRepository("$URL$");
-  if (URL.empty())
-    URL = SVNRepository.split(':').second;
+  if (URL.empty()) {
+    URL = SVNRepository.slice(SVNRepository.find(':'),
+                              SVNRepository.find("/lib/Basic"));
+  }
 
   // Strip off version from a build from an integration branch.
   URL = URL.slice(0, URL.find("/src/tools/clang"));