fix: Fix errors that occur during parallel builds

.travis.yml

@@ -12,7 +12,7 @@ jobs:
         - postgresql-11
         - postgresql-server-dev-11
     script:
-    - sudo make install
+    - sudo make install -j$(nproc)
     - make installcheck
     after_failure: cat regress/regression.diffs
   - name: documentation

Makefile

@@ -71,23 +71,28 @@ REGRESS = scan \
           cypher_match \
           cypher_set \
           cypher_remove \
-	  cypher_delete \
+          cypher_delete \
           cypher_with \
           drop
 
 ag_regress_dir = $(srcdir)/regress
 REGRESS_OPTS = --load-extension=age --inputdir=$(ag_regress_dir) --outputdir=$(ag_regress_dir) --temp-instance=$(ag_regress_dir)/instance --port=61958
 
 ag_regress_out = instance/ log/ results/ regression.*
-EXTRA_CLEAN = $(addprefix $(ag_regress_dir)/, $(ag_regress_out))
+EXTRA_CLEAN = $(addprefix $(ag_regress_dir)/, $(ag_regress_out)) src/backend/parser/cypher_gram.c src/include/parser/cypher_gram_def.h
 
 ag_include_dir = $(srcdir)/src/include
-PG_CPPFLAGS = -I$(ag_include_dir)
+PG_CPPFLAGS = -I$(ag_include_dir) -I$(ag_include_dir)/parser
 
 PG_CONFIG = pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)
 include $(PGXS)
 
-src/backend/parser/cypher_gram.c: BISONFLAGS += --defines=$(ag_include_dir)/parser/$(basename $(notdir $@))_def.h
+src/include/parser/cypher_gram_def.h: src/backend/parser/cypher_gram.c
+
+src/backend/parser/cypher_gram.c: BISONFLAGS += --defines=src/include/parser/cypher_gram_def.h
+
+src/backend/parser/cypher_parser.o: src/backend/parser/cypher_gram.c
+src/backend/parser/cypher_keywords.o: src/backend/parser/cypher_gram.c
 
 src/backend/parser/ag_scanner.c: FLEX_NO_BACKUP=yes