pgsql-7.4.1 build on darwin-x86

Ran all regression tests, and the result: All 93 tests passed.  No
regression.diffs created.  I can forward all the results files that are
created.  Just had to modify the src/include/ports/darwin.h with the
additions (+) noted:

#define __darwin__      1

#if defined(__ppc__)
#define HAS_TEST_AND_SET
#endif

+#if defined(__i386__)
+#define HAS_TEST_AND_SET
+#endif

#if defined(__ppc__)
typedef unsigned int slock_t;

#else
typedef unsigned char slock_t;

#endif