Overlays: Fix tool not to find os as a dependency unless it depends on

os/activity.h or os/log.h. Update cmake files again, hardcoding a Darwin
dependency. The script does not notice that Foundation depends on
CoreGraphics, so add that manually.

Also found that MapKit is supported on WATCHOS but we didn't have dependencies
for that.

Favor one line per supported SDK instead of catch-all dependency lines.

Distinguish from SDKs which have no dependencies vs SDKs which are
unsupported on a particular platform by printing `unsupported` to the
console and remove the line in the cmake file because it should
not exist anyway.

This full cleanup was not done before because of circularity detected by the
util, which has since been fixed.

Support directories with spaces.

utils/find-overlay-dependencies-loop.sh

@@ -27,7 +27,11 @@ case $# in
   usage ;;
 esac
 
-# Don't update XCTest
-for overlay in $(find ./stdlib/public/SDK/ -depth 1 -type d ! -name XCTest -exec basename \{\} \;); do
-  $SCRIPT $overlay $1
+# Don't update XCTest, handle spaces in directories
+for f in ./stdlib/public/SDK/*/; do
+  name=`basename "${f}"`
+  if [[ "${name}" == "XCTest" ]]; then
+    continue
+  fi
+  $SCRIPT "${name}" "$1"
 done