std/rec/test: test dbGet() and dbPut() for array field

test with waveform record to check that DBADDR
modifications aren't seen by the caller.

src/std/rec/test/arrayOpTest.db

@@ -0,0 +1,4 @@
+record(waveform, "wfrec") {
+    field(NELM, "10")
+    field(FTVL, "LONG")
+}