misc/ios: quote paths

The paths may contain spaces. Quote them.

Change-Id: I1f67085a1e7c40f60282c2fea7104fb44a01e310
Reviewed-on: https://go-review.googlesource.com/c/go/+/254739
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>

Author: cherrymui

misc/ios/clangwrap.sh

@@ -15,4 +15,4 @@ else
 	exit 1
 fi
 
-exec $CLANG -arch $CLANGARCH -isysroot $SDK_PATH -mios-version-min=10.0 "$@"
+exec "$CLANG" -arch $CLANGARCH -isysroot "$SDK_PATH" -mios-version-min=10.0 "$@"