configure: filter link flags separately for MSVC

This avoids adding flags that cl.exe doesn't understand.

Fixes cases where external libraries pkg-config file adds `-L` to the
cflags, strip it before passing to cl.exe.

Signed-off-by: Kacper Michajłow <kasper93@gmail.com>

configure

@@ -4925,7 +4925,7 @@ msvc_common_flags(){
             -lstdc++)             ;;
             -l*)                  echo ${flag#-l}.lib ;;
             -LARGEADDRESSAWARE)   echo $flag ;;
-            -L*)                  echo -libpath:${flag#-L} ;;
+            -L*) [ "$_flags_type" = "link" ] && echo -libpath:${flag#-L} ;;
             -Wl,*)                ;;
             *)                    echo $flag ;;
         esac
@@ -4947,6 +4947,12 @@ msvc_flags(){
     done
 }
 
+msvc_flags_link(){
+    _flags_type=link
+    msvc_flags "$@"
+    unset _flags_type
+}
+
 icl_flags(){
     msvc_common_flags "$@"
     for flag; do
@@ -5173,12 +5179,13 @@ probe_cc(){
         _cflags_noopt="-O1"
         if $_cc -nologo- 2>&1 | grep -q Linker; then
             _ld_o='-out:$@'
+            _flags_filter=msvc_flags_link
         else
             _ld_o='-Fe$@'
+            _flags_filter=msvc_flags
         fi
         _cc_o='-Fo$@'
         _cc_e='-P -Fi$@'
-        _flags_filter=msvc_flags
         _ld_lib='lib%.a'
         _ld_path='-libpath:'
         _flags='-nologo'