libretro-mame: fix cross compilation

Don't set PTR64=0 on 32bit archs, instead set ARCHITECTURE to an empty
string. That way we don't need to patch out hardcoded -m32 arguments.

While at it, disable the bgfx hw renderers, or that pile of build crap
tries to include X11 headers.

packages/emulation/libretro-mame/package.mk

@@ -17,21 +17,18 @@ PKG_LIBNAME="mame_libretro.so"
 PKG_LIBPATH="$PKG_LIBNAME"
 PKG_LIBVAR="MAME_LIB"
 
-make_target() {
+pre_make_target() {
-  PTR64="0"
+  PKG_MAKE_OPTS_TARGET=" \
-  NOASM="0"
+    REGENIE=1 VERBOSE=1 NOWERROR=1 PYTHON_EXECUTABLE=python3 CONFIG=libretro \
+    LIBRETRO_OS="unix" ARCH="" PROJECT="" LIBRETRO_CPU="${ARCH}" DISTRO="debian-stable" \
+    CROSS_BUILD="1" OVERRIDE_CC="${CC}" OVERRIDE_CXX="${CXX}" \
+    TARGET="mame" SUBTARGET="arcade" PLATFORM="${ARCH}" RETRO=1 OSD="retro""
 
   if [ "$ARCH" = "arm" ]; then
-    NOASM="1"
+    PKG_MAKE_OPTS_TARGET+=" NOASM="1" ARCHITECTURE="""
   elif [ "$ARCH" = "x86_64" ]; then
-    PTR64="1"
+    PKG_MAKE_OPTS_TARGET+=" NOASM="0" PTR64="1""
   fi
-
-  make REGENIE=1 VERBOSE=1 NOWERROR=1 PYTHON_EXECUTABLE=python3 CONFIG=libretro \
-       LIBRETRO_OS="unix" ARCH="" PROJECT="" LIBRETRO_CPU="$ARCH" DISTRO="debian-stable" \
-       CROSS_BUILD="1" OVERRIDE_CC="$CC" OVERRIDE_CXX="$CXX" \
-       PTR64="$PTR64" TARGET="mame" \
-       SUBTARGET="arcade" PLATFORM="$ARCH" RETRO=1 OSD="retro"
 }
 
 post_make_target() {

packages/emulation/libretro-mame/patches/bgfx.patch

@@ -0,0 +1,11 @@
+--- a/3rdparty/bgfx/src/config.h	2020-01-14 08:42:35.023108564 +0100
++++ b/3rdparty/bgfx/src/config.h	2020-01-14 08:42:39.527041246 +0100
+@@ -12,7 +12,7 @@
+ #	define BGFX_CONFIG_DEBUG 0
+ #endif // BGFX_CONFIG_DEBUG
+ 
+-#if !defined(BGFX_CONFIG_RENDERER_DIRECT3D9) \
++#if 0 && !defined(BGFX_CONFIG_RENDERER_DIRECT3D9) \
+ 	&& !defined(BGFX_CONFIG_RENDERER_DIRECT3D11) \
+ 	&& !defined(BGFX_CONFIG_RENDERER_DIRECT3D12) \
+ 	&& !defined(BGFX_CONFIG_RENDERER_METAL) \

packages/emulation/libretro-mame/patches/genie.patch

@@ -0,0 +1,17 @@
+--- a/3rdparty/genie/build/gmake.linux/genie.make	2020-01-14 06:27:22.077161784 +0100
++++ b/3rdparty/genie/build/gmake.linux/genie.make	2020-01-14 06:27:49.856857764 +0100
+@@ -28,8 +28,12 @@
+   RM    = $(SILENT) del /F "$(subst /,\\,$(1))" 2> nul || exit 0
+ endif
+ 
+-CC  = gcc
+-CXX = g++
++CC  = $(HOST_CC)
++CXX = $(HOST_CXX)
++CPPFLAGS = $(HOST_CPPFLAGS)
++CFLAGS = $(HOST_CFLAGS)
++CXXFLAGS = $(HOST_CXXFLAGS)
++LDFLAGS = $(HOST_LDFLAGS)
+ AR  = ar
+ 
+ ifndef RESCOMP