winpthreads: Add windres-rc, a wrapper for windres to rc

Signed-off-by: Antonin Décimo <antonin@tarides.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
diff --git a/mingw-w64-libraries/winpthreads/configure.ac b/mingw-w64-libraries/winpthreads/configure.ac
index e723167..b691ad0 100644
--- a/mingw-w64-libraries/winpthreads/configure.ac
+++ b/mingw-w64-libraries/winpthreads/configure.ac
@@ -19,6 +19,11 @@
 AM_PROG_AS
 AM_PROG_AR
 
+AS_CASE([$CC],
+  [*cl|*cl.exe],
+    [RC="$am_aux_dir/windres-rc rc.exe"]])
+AC_SUBST([RCFLAGS])
+
 # Libtool 2.4 should check them correctly
 # AC_CHECK_TOOLS([AR],[ar],[:])
 
@@ -50,7 +55,5 @@
 # mingw-w64 should already have them
 #AC_CHECK_FUNCS([ftime gettimeofday memset])
 
-AC_SUBST([RCFLAGS])
-
 AC_CONFIG_FILES([Makefile tests/Makefile])
 AC_OUTPUT