Ensure that numeric.c compiles with other NBASE values.

As noted in the comments, support for different NBASE values is really
only of historical interest, but as long as we're keeping it, we might
as well make sure that it compiles.

Joel Jacobson

Discussion: https://postgr.es/m/06712c29-98e9-43b3-98da-f234d81c6e49%40app.fastmail.com

src/backend/utils/adt/numeric.c

@@ -4245,7 +4245,15 @@ int64_div_fast_to_numeric(int64 val1, int log10val2)
 	 */
 	if (m > 0)
 	{
+#if DEC_DIGITS == 4
 		static int	pow10[] = {1, 10, 100, 1000};
+#elif DEC_DIGITS == 2
+		static int	pow10[] = {1, 10};
+#elif DEC_DIGITS == 1
+		static int	pow10[] = {1};
+#else
+#error unsupported NBASE
+#endif
 
 		StaticAssertDecl(lengthof(pow10) == DEC_DIGITS, "mismatch with DEC_DIGITS");