Remove code duplication from StringImpl create()/reallocate() methods
https://bugs.webkit.org/show_bug.cgi?id=118355

Reviewed by Andreas Kling.

StringImpl create()/reallocate() methods accepting LChar and UChar used to have
duplicated code. The code duplication is removed now via used templates.

* wtf/text/StringImpl.cpp:
(WTF::StringImpl::constructInternal):
(WTF::LChar):
(WTF::StringImpl::createUninitializedInternal):
(WTF::StringImpl::createUninitialized):
(WTF::StringImpl::reallocateInternal):
(WTF::StringImpl::reallocate):
(WTF::StringImpl::createInternal):
(WTF::StringImpl::create):
* wtf/text/StringImpl.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@152415 268f45cc-cd09-0410-ab3c-d52691b4dbfc