Do not crash when trying to define and call a non-standard
strcpy(unsigned char *, unsigned char *) during analysis.
At the same time, do not try to actually evaluate the call.
Differential Revision: https://reviews.llvm.org/D39422
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@317565 91177308-0d34-0410-b5e6-96231b3b80d8
Artem Dergachev