mapi: Workaround a bug in makedepend.

makedepend would crash when a source includes a header indirectly, such
as

  #define HEADER "some-header.h"
  #include HEADER

Do not define HEADER (makedepend would detects this as an incomplete
include) and add the dependency manually in the Makefile.

This should hopefully fix bug #33374.

src/mapi/glapi/Makefile

@@ -13,11 +13,12 @@ include $(MAPI)/sources.mak
 glapi_CPPFLAGS := \
 	-I$(TOP)/include \
 	-I$(TOP)/src/mapi \
-	-I$(TOP)/src/mesa \
-	-DMAPI_ABI_HEADER=\"glapi/glapi_mapi_tmp.h\"
+	-I$(TOP)/src/mesa
 
 ifeq ($(SHARED_GLAPI),1)
-glapi_CPPFLAGS += -DMAPI_MODE_BRIDGE
+glapi_CPPFLAGS += \
+	-DMAPI_MODE_BRIDGE \
+	-DMAPI_ABI_HEADER=\"glapi/glapi_mapi_tmp.h\"
 glapi_SOURCES := $(addprefix $(MAPI)/, $(MAPI_BRIDGE_SOURCES))
 
 glapi_GLAPI_OBJECTS :=
@@ -58,10 +59,19 @@ clean:
 	-rm -f lib$(TARGET).a
 	-rm -f depend depend.bak
 
+ifeq ($(SHARED_GLAPI),1)
+# workaround a bug in makedepend
+makedepend_CPPFLAGS := \
+	$(filter-out -DMAPI_ABI_HEADER=%, $(glapi_CPPFLAGS))
+$(glapi_OBJECTS): glapi_mapi_tmp.h
+else
+makedepend_CPPFLAGS := $(glapi_CPPFLAGS)
+endif
+
 depend: $(glapi_SOURCES)
 	@ echo "running $(MKDEP)"
 	@ touch depend
-	@$(MKDEP) $(MKDEP_OPTIONS) -f- $(DEFINES) $(glapi_CPPFLAGS) \
+	@$(MKDEP) $(MKDEP_OPTIONS) -f- $(DEFINES) $(makedepend_CPPFLAGS) \
 		$(glapi_SOURCES) 2>/dev/null | sed -e 's,^$(MAPI)/,,' > depend
 
 -include depend