Additional fixes for parallel make

Add some additional dependencies to constrain the build order to prevent
parallel make from failing.  In the case of src/Makefile, this is likely to be
too complicated to be worth maintaining, so just add .NOTPARALLEL to get the
old for-loop-like behavior.

More fine-tuning might be necessary for some platforms or configurations.

src/Makefile

@@ -26,6 +26,10 @@ SUBDIRS = \
 	makefiles \
 	test/regress
 
+# There are too many interdependencies between the subdirectories, so
+# don't attempt parallel make here.
+.NOTPARALLEL:
+
 $(recurse)
 
 install: install-local

src/interfaces/Makefile

@@ -15,3 +15,5 @@ include $(top_builddir)/src/Makefile.global
 SUBDIRS = libpq ecpg
 
 $(recurse)
+
+all-ecpg-recurse: all-libpq-recurse

src/interfaces/ecpg/Makefile

@@ -6,7 +6,8 @@ SUBDIRS = include pgtypeslib ecpglib compatlib preproc
 
 $(recurse)
 
-all-compatlib-recursive: all-ecpglib-recursive
+all-compatlib-recurse: all-ecpglib-recurse
+all-ecpglib-recurse: all-pgtypeslib-recurse
 
 clean distclean maintainer-clean:
 	$(MAKE) -C test clean