Fix Appveyor (#295)

Makefile.common

+# Appveyor Config
+ifeq ($(appveyor),1)
+	FLAGS += -DPRId64=I64d -DPRIu64=I64u -DPRIuPTR=Iu
+endif
+
 # ChaiLove
 SOURCES_CXX := $(wildcard \
 	$(CORE_DIR)/src/*.cpp \
@@ -39,6 +44,9 @@ SOURCES_C += $(wildcard \
 	$(CORE_DIR)/vendor/libretro-common/file/config_file_userdata.c \
 	$(CORE_DIR)/vendor/libretro-common/file/file_path.c \
 	$(CORE_DIR)/vendor/libretro-common/compat/compat_strl.c \
+	$(CORE_DIR)/vendor/libretro-common/compat/fopen_utf8.c \
+	$(CORE_DIR)/vendor/libretro-common/compat/compat_posix_string.c \
+	$(CORE_DIR)/vendor/libretro-common/encodings/encoding_utf.c \
 	$(CORE_DIR)/vendor/libretro-common/file/config_file_userdata.c \
 	$(CORE_DIR)/vendor/libretro-common/file/config_file.c \
 	$(CORE_DIR)/vendor/libretro-common/lists/string_list.c \

appveyor.yml

@@ -17,6 +17,7 @@ environment:
   TARGET: chailove_libretro.dll
   platform: win
   system_platform: win
+  appveyor: 1
 
 init:
   - git config --global core.autocrlf input
@@ -32,7 +33,7 @@ before_build:
   - gcc --version
 
 build_script:
-  - make
+  - make appveyor=1
 
 # TODO: Add automated testing
 #before_test: