wrappers: Use --{start,end}-no-unused-arguments instead of -Qunused-arguments

This makes warnings for other unused arguments visible to the user.

This requires a version of llvm-project past
50ec1306d060e46e0d53c9f5d8a052e1b0d10d3b (Jan 2022) which added these
new options.

wrappers/clang-target-wrapper.sh

@@ -45,6 +45,7 @@ fi
 # If changing this wrapper, change clang-target-wrapper.c accordingly.
 CLANG="$DIR/clang"
 FLAGS=""
+FLAGS="$FLAGS --start-no-unused-arguments"
 case $EXE in
 clang++|g++|c++)
     FLAGS="$FLAGS --driver-mode=g++"
@@ -87,6 +88,6 @@ FLAGS="$FLAGS -rtlib=compiler-rt"
 FLAGS="$FLAGS -unwindlib=libunwind"
 FLAGS="$FLAGS -stdlib=libc++"
 FLAGS="$FLAGS -fuse-ld=lld"
-FLAGS="$FLAGS -Qunused-arguments"
+FLAGS="$FLAGS --end-no-unused-arguments"
 
 $CCACHE "$CLANG" $FLAGS "$@"