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

--- a/Makefile
+++ b/Makefile
@@ -34,6 +34,8 @@ NOT_OBJ_FILES := src/pg_query_enum_defs.
 OBJ_FILES := $(filter-out $(NOT_OBJ_FILES), $(SRC_FILES:.c=.o))
 
 override CFLAGS += -g -I. -I./vendor -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)
 
 override PG_CONFIGURE_FLAGS += -q --without-readline --without-zlib --without-icu
 
