Fix build on Solaris 11.

Patch by Vladimir Voskresensky. The erros were:

Path.inc:274:3: error: ‘Dl_info’ was not declared in this scope
...

and

usr/include/spawn.h:52:14: error: expected ‘,’ or ‘...’ before ‘argv’

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192185 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/Unix/Program.inc

@@ -36,6 +36,9 @@
 #include <unistd.h>
 #endif
 #ifdef HAVE_POSIX_SPAWN
+#ifdef __sun__
+#define  _RESTRICT_KYWD
+#endif
 #include <spawn.h>
 #if !defined(__APPLE__)
   extern char **environ;