dependencies: Also strip git version from llvm version

If LLVM is built from a git mirror instead of from SVN it will have
"git-<very short sha>" at the end of the version. We need to remove that
so that version comparison will work correctly.

Fixes: #2786

mesonbuild/dependencies/dev.py

@@ -150,7 +150,12 @@ class LLVMDependency(ConfigToolDependency):
         # Currently meson doesn't really attempt to handle pre-release versions,
         # so strip the 'svn' off the end, since it will probably cuase problems
         # for users who want the patch version.
+        #
+        # If LLVM is built from svn then "svn" will be appended to the version
+        # string, if it's built from a git mirror then "git-<very short sha>"
+        # will be appended instead.
         self.version = self.version.rstrip('svn')
+        self.version = self.version.split('git')[0]
 
         self.provided_modules = self.get_config_value(['--components'], 'modules')
         modules = stringlistify(extract_as_list(kwargs, 'modules'))