Use 'check_symbol_exists' instead of 'check_function_exists' for finding isatty.  This change allows Xcode generated projects to have HAVE_ISATTY to be properly defined.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147215 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed