android: fix cx11 compile (#569)

jni/Android.mk

@@ -16,6 +16,7 @@ COREFLAGS := -DCORE_NAME=\"$(EMUTYPE)\" \
   $(INCFLAGS) $(COMMONFLAGS) \
   -DHAVE_INET_ATON \
   -DHAVE_7ZIP -D_7ZIP_ST \
+  -DHAVE_CXX11 \
   -D_INTTYPES_H
 
 GIT_VERSION := " $(shell git rev-parse --short HEAD || echo unknown)"

jni/Application.mk

@@ -7,4 +7,4 @@ APP_ABI := all
 # This should be investigated more in the future.
 APP_CFLAGS += -Wno-error=format-security -Ofast
 APP_STL := c++_static
-APP_PLATFORM := android-16
+APP_PLATFORM := android-21