IDL compiler: fix executable bit on v8_globals.py

Cleanup; for some reason this got created with an executable bit.

Patch is file mode change only; can review at:
https://codereview.chromium.org/49713004/patch/1/10001

Need to dcommit b/c CQ can't handle executable bit changes, per bug:
Commit queue doesn't remove the svn:executable bit properly when asked on file copy
https://code.google.com/p/chromium/issues/detail?id=162196

BUG=239771
NOTRY=true
TBR=haraken

Review URL: https://codereview.chromium.org/49713004

git-svn-id: svn://svn.chromium.org/blink/trunk@161001 bbb929c8-8fbe-4397-9dbb-9b2b20218538