8209115: adjust libsplashscreen linux ppc64le builds for easier libpng update

Reviewed-by: andrew, phh
Backport-of: e4fdd0391733756f5b898371a66b38869d625c77

Author: martinuy

jdk/make/lib/Awt2dLibraries.gmk

@@ -1159,6 +1159,12 @@ ifndef BUILD_HEADLESS_ONLY
       -DPNG_ARM_NEON_OPT=0 -DPNG_ARM_NEON_IMPLEMENTATION=0 \
       $(foreach dir, $(LIBSPLASHSCREEN_DIRS), -I$(dir))
 
+  ifeq ($(OPENJDK_TARGET_OS), linux)
+    ifeq ($(OPENJDK_TARGET_CPU_ARCH), ppc)
+      LIBSPLASHSCREEN_CFLAGS += -DPNG_POWERPC_VSX_OPT=0
+    endif
+  endif
+
   ifeq ($(OPENJDK_TARGET_OS), macosx)
     LIBSPLASHSCREEN_CFLAGS := -I$(JDK_TOPDIR)/src/macosx/native/sun/awt/splashscreen \
         $(LIBSPLASHSCREEN_CFLAGS)

jdk/src/share/native/sun/awt/libpng/pngpriv.h

@@ -293,13 +293,10 @@
 #  endif
 #endif /* PNG_MIPS_MSA_OPT > 0 */
 
-#ifdef PNG_POWERPC_VSX_API_SUPPORTED
 #if PNG_POWERPC_VSX_OPT > 0
 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
 #  define PNG_POWERPC_VSX_IMPLEMENTATION 1
 #endif
-#endif
-
 
 
 /* Is this a build of a DLL where compilation of the object modules requires