Gregor Jasny authored Feb 22, 2015 and Brad King committed Feb 23, 2015

Otherwise find_library is unable to lookup the XCTest framework which
is not located in the SDK serach path:

In the 10.10 SDK the SDK frameworks are located here:

  $DEVELOPER_DIR/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/Frameworks

whereas the Platform SDKs are located here:

  $DEVELOPER_DIR/Platforms/MacOSX.platform/Developer/Library/Frameworks

Signed-off-by: Gregor Jasny <gjasny@googlemail.com>