Add hack (provided by Jonathan Sauer) to fall back to assuming Xcode is installed in /Developer

when using Python < 2.7.0.  This is the case on Snow Leopard, where the tools are always
installed in /Developer.  This isn't a proper fix for really figuring out where Xcode
is installed, but should work to fix an obvious problem on Snow Leopard.

llvm-svn: 160321

clang/tools/scan-build/set-xcode-analyzer

@@ -75,7 +75,11 @@ def main():
     print "(+) Using the Clang bundled with Xcode"
     path = options.default
   
-  xcode_path = subprocess.check_output(["xcode-select", "-print-path"])
+  try:
+    xcode_path = subprocess.check_output(["xcode-select", "-print-path"])
+  except AttributeError:
+    # Fall back to the default install location when using Python < 2.7.0
+    xcode_path = "/Developer"
   if (re.search("Xcode.app", xcode_path)):
     # Cut off the 'Developer' dir, as the xcspec lies in another part
     # of the Xcode.app subtree.