[json, test] Fix the json.td test - the path to python could contain spaces

[stella.stamenova]

Summary

The path to the python executable can contain spaces, so it should be specified with quotes.

[simon_tatham]

LGTM. (But I learned something new when I dug into lit to find out why you could get away with using single quotes – I would have expected that only double quotes would work on Windows!)

llvm/trunk/test/TableGen/JSON.td

-// RUN: llvm-tblgen -dump-json %s | %python %S/JSON-check.py %s
+// RUN: llvm-tblgen -dump-json %s | '%python' %S/JSON-check.py %s
 
 // CHECK: data['!tablegen_json_version'] == 1
 
 // CHECK: all(data[s]['!name'] == s for s in data if not s.startswith("!"))
 
 class Base {}
 class Intermediate : Base {}
 class Derived : Intermediate {}