Ensure nested ternary operator unfolding uses a new scope to avoid redefinition of the same temporary variable.

TRAC #22629
Signed-off-by: Jamie Madill
Signed-off-by: Shannon Woods
Author: Nicolas Capens

git-svn-id: https://angleproject.googlecode.com/svn/trunk@1835 736b8ea6-26fd-11df-bfd4-992fa37f6226