GCC warns about removing const with a c-style cast.

llvm-svn: 188259
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
index 768c338..3731618 100644
--- a/llvm/lib/Support/Unix/Process.inc
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -280,7 +280,7 @@
   //
   // The 'tigetnum' routine returns -2 or -1 on errors, and might return 0 if
   // the terminfo says that no colors are supported.
-  if (tigetnum((char *)"colors") > 0)
+  if (tigetnum(const_cast<char *>("colors")) > 0)
     return true;
 #endif