Pull VLA size checker into its own files. 
Split it to two checkers, one for undefined size, 
the other for zero size, so that we don't need to query the size
when emitting the bug report.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@85895 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed