jdk/jdk (+jdk12) Build failure on OSX 10.11

[Baesken, Matthias]

Hello,  I noticed that we fail  on OSX 10.11  in the build   .  Reason is  that   NSWindowStyleMaskDocModalWindow  is used since :

https://hg.openjdk.java.net/jdk/jdk/rev/6daafebf8189

8208543: [macos] Support for apple.awt.documentModalSheet incomplete

Which is 10.12+ functionality . See

https://developer.apple.com/documentation/appkit/nswindowstylemask/nswindowstylemaskdocmodalwindow?language=objc

NSWindowStyleMaskDocModalWindow
The window is a document-modal panel (or a subclass of NSPanel<https://developer.apple.com/documentation/appkit/nspanel?language=objc>).
macOS 10.12+



I would prefer to test for  minimum  10.12  already  in  configure  , what do you think ?

Best regards, Matthias