Build fails after fix for JDK-8260640

In file included from ./open/src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/EncoderManager.m:27:
./open/src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLContext.h:30:10: fatal error: 'sun_java2d_metal_MTLContext.h' file not found
#include "sun_java2d_metal_MTLContext.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
lib/Awt2dLibraries.gmk:845: recipe for target '.../build/macosx-x64/support/native/java.desktop/libawt_lwawt/EncoderManager.o' failed