Include server include files for missing atomics-{ia64,hppa}.h

--- a/Makefile
+++ b/Makefile
@@ -34,6 +34,8 @@ SRC_FILES := $(wildcard src/*.c src/post
 OBJ_FILES := $(SRC_FILES:.c=.o)
 
 override CFLAGS += -g -I. -I./vendor -I./src/include -I./src/postgres/include -Wall -Wno-unused-function -Wno-unused-value -Wno-unused-variable -fno-strict-aliasing -fwrapv -fPIC
+PG_CONFIG = pg_config
+override CFLAGS += -I$(shell $(PG_CONFIG) --includedir-server)
 
 ifeq ($(OS),Windows_NT)
 override CFLAGS += -I./src/postgres/include/port/win32
