The current jdk9 tip fails to build from source on aarch64 with the following error message

/home/ed/build/1504/dev/build/linux-aarch64-normal-server-release/support/native/java.desktop/libsplashscreen/pngrutil.o: In function `png_init_filter_functions':
/home/ed/build/1504/dev/jdk/src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c:3947: undefined reference to `png_init_filter_functions_neon'
collect2: error: ld returned 1 exit status

This was introduced at changeset 11769

changeset: 11769:cb75299d5933
user: azvegint
date: Mon Jan 19 20:02:31 2015 +0300
files: src/java.desktop/share/native/libsplashscreen/libpng/CHANGES src/java.desktop/share/native/libsplashscreen/libpng/LICENSE src/java.desktop/share/native/libsplashscreen/libpng/README src/java.desktop/share/native/libsplashscreen/libpng/png.c src/java.desktop/share/native/libsplashscreen/libpng/png.h src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h src/java.desktop/share/native/libsplashscreen/libpng/pngdebug.h src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c src/java.desktop/share/native/libsplashscreen/libpng/pngget.c src/java.desktop/share/native/libsplashscreen/libpng/pnginfo.h src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h src/java.desktop/share/native/libsplashscreen/libpng/pngread.c src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c src/java.desktop/share/native/libsplashscreen/libpng/pngset.c src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h src/java.desktop/share/native/libsplashscreen/libpng/pngtest.c src/java.desktop/share/native/libsplashscreen/libpng/pngtrans.c src/java.desktop/share/native/libsplashscreen/libpng/pngwio.c src/java.desktop/share/native/libsplashscreen/libpng/pngwrite.c src/java.desktop/share/native/libsplashscreen/libpng/pngwtran.c src/java.desktop/share/native/libsplashscreen/libpng/pngwutil.c
description:
8069198: Upgrade image library
Reviewed-by: ahgross, bae, mschoene, serb

This changeset seems to introduce some ARM Neon optimisations, however I cannot seem to access the associated bug report JDK-8069198 as it seems I do not have suitable privileges to read the report.

The problem is that it is also attempting to build this code for AARCH64 resulting in the above undefined symbol.

The attached patch fixes this problem by adding defined(__arm__) to ensure this code is only compiled on 32 bit ARM.