db: patch to always use time_t for tv_nsec

srcpkgs/db/patches/time64.patch

@@ -0,0 +1,18 @@
+By the comment's own admission, this cannot affect on-disk nor ABI because
+'long' varies per architecture.  So, this change is always correct.
+
+--- src/dbinc/clock.h	2013-09-09 15:35:08.000000000 +0000
++++ src/dbinc/clock.h	2020-01-31 19:22:11.630000000 +0000
+@@ -54,11 +54,7 @@
+  */
+ typedef struct {
+ 	time_t	tv_sec;				/* seconds */
+-#ifdef HAVE_MIXED_SIZE_ADDRESSING
+-	int32_t tv_nsec;
+-#else
+-	long	tv_nsec;			/* nanoseconds */
+-#endif
++	time_t	tv_nsec;			/* nanoseconds */
+ } db_timespec;
+ 
+ /* Operations on timespecs */