Fix breakage in winegcc build script.

Apparently when I started using _wfopen in commit 8bd75b85ed, the
winegcc build (which I mostly use for Coverity Scan) stopped working,
because _wfopen isn't included in any of the libraries I explicitly
had on my link line.

Rather than mess about with cmake, it's easier to just bodge it in the
winegcc wrapper script, since we had one of those already.

cmake/winegcc

@@ -5,6 +5,7 @@
 # options that CMake gets wrong.
 
 init=true
+link=true
 for arg in init "$@"; do
     if $init; then
         set --
@@ -21,9 +22,18 @@ for arg in init "$@"; do
         # suffix.
         -l*.lib) set -- "$@" "${arg%.lib}";;
 
+        # Options that mean we're not linking.
+        -E | -S | -c) link=false  set -- "$@" "$arg";;
+
         # Anything else, we leave unchanged.
         *) set -- "$@" "$arg";;
     esac
 done
 
+if $link; then
+    # winegcc requires this library for _wfopen
+    set -- "$@" -lucrtbase
+fi
+
+echo "$@" >&2
 exec winegcc "$@"