make: Fix MinGW build machinery machinery

This commit makes it possible to successfully run "make all" against ytools'
again, with TARGET_TUPLE set to i686-ms-w64-mingw. Lots of minor and major
tweaks here and there.

The biggest diff is a move of the architecture-related definitions into
platform.mk. The are needed pretty early on, so that seems reasonable.

Making this work again is part of the larger effort to support cross
buildchains in a more concise way, i.e. without so many if ($(TARGET),mingw))
all over the place. TARGET's relevance should dwindle, until it's finally taken
over by the TARGET_XXX variables extracted from TARGET_TUPLE or TARGET_TRIPLET.

Signed-off-by: Jan Lindemann <jan@janware.com>

make/defs-cpp.mk

@@ -19,6 +19,10 @@ else ifeq ($(ARCH),aarch64)
   PROJECT_LDFLAGS       +=
 endif
 
+ifeq ($(findstring $(TARGET_OS),linux),)
+  USE_SYSTEMD           := false
+endif
+
 ifeq ($(DEVELOPMENT),true)
   export G_SLICE=always-malloc
   export G_DEBUG=gc-friendly,resident-modules
@@ -66,6 +70,8 @@ endif
 
 ifeq ($(TARGET),mingw)
  ifneq ($(wildcard /usr/bin/i686-w64-mingw32-gcc),)
+  PROJECT_CFLAGS      += -D_WINDOWS
+  PROJECT_CPPFLAGS    += -D_WINDOWS
   MINGW_SYS_ROOT      ?= /usr/i686-w64-mingw32/sys-root/mingw
   CROSS_TOOL_DIR      ?=
   CROSS_TOOL_BIN_PREFIX ?= $(CROSS_TOOL_DIR)/usr/bin/i686-w64-mingw32-
@@ -217,6 +223,8 @@ endif
 ifeq ($(TARGET),mingw)
 BUILD_CFLAGS          += -DWIN32
 BUILD_CPPFLAGS        += -DWIN32
+# see https://stackoverflow.com/questions/4492799
+BUILD_LDFLAGS         += -fstack-protector
 endif
 
 ifeq ($(LIBTYPE),shared)