More character range checks.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1421 2f5784b3-3f2a-0410-8824-cb99058d5e15
JIT: Improved character read in UTF mode.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1422 2f5784b3-3f2a-0410-8824-cb99058d5e15