[WinCairo] Compile fix.
https://bugs.webkit.org/show_bug.cgi?id=118461

Patch by peavo@outlook.com <peavo@outlook.com> on 2013-07-12
Reviewed by Brent Fulgham.

* config.h: Only enable AVFOUNDATION for Windows if CoreGraphics is used.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@152593 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Improve StringImpl::constructInternal() method
https://bugs.webkit.org/show_bug.cgi?id=118503

Reviewed by Benjamin Poulain.

StringImpl::constructInternal used 'if ()' statement to decide which constructor
to invoke hence compiler had to compile both branches even though optimizer would
have then removed one of those, and as the function is inline it could affect
slightly the compilation time.

The problem is solved via template specialization.

* wtf/text/StringImpl.h:
(WTF::LChar):
(WTF::UChar):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@152595 268f45cc-cd09-0410-ab3c-d52691b4dbfc