Workaround module test failures by removing the version info from module hashes.

PR12196: The module hash strings are not actually hashing the compiler version
string; the entire version string is being included in the hash.  Depending on
the module cache directory name, that can lead to failures where the path
names become too long.  As a temporary workaround, just remove the version
string from the hash.

llvm-svn: 152266