8282588: [11] set harfbuzz compilation flag to -std=c++11

Reviewed-by: mdoerr

Author: MBaesken

make/lib/Awt2dLibraries.gmk

@@ -542,6 +542,8 @@ ifeq ($(USE_EXTERNAL_HARFBUZZ), true)
 else
   LIBFONTMANAGER_EXTRA_SRC = libharfbuzz
   HARFBUZZ_CFLAGS := -DHAVE_OT -DHAVE_FALLBACK -DHAVE_UCDN -DHAVE_ROUND
+  # Modern HarfBuzz requires c++11.
+  HARFBUZZ_CXXFLAGS := -std=c++11
 
   ifneq ($(OPENJDK_TARGET_OS), windows)
     HARFBUZZ_CFLAGS += -DGETPAGESIZE -DHAVE_MPROTECT -DHAVE_PTHREAD \
@@ -624,7 +626,7 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBFONTMANAGER, \
         AccelGlyphCache.c, \
     TOOLCHAIN := TOOLCHAIN_LINK_CXX, \
     CFLAGS := $(CFLAGS_JDKLIB) $(LIBFONTMANAGER_CFLAGS), \
-    CXXFLAGS := $(CXXFLAGS_JDKLIB) $(LIBFONTMANAGER_CFLAGS), \
+    CXXFLAGS := $(CXXFLAGS_JDKLIB) $(LIBFONTMANAGER_CFLAGS) $(HARFBUZZ_CXXFLAGS), \
     OPTIMIZATION := $(LIBFONTMANAGER_OPTIMIZATION), \
     CFLAGS_windows = -DCC_NOEX, \
     EXTRA_HEADER_DIRS := $(LIBFONTMANAGER_EXTRA_HEADER_DIRS), \