encoding/openapi: simplify based on user-defined format

For instance, don't use minimum and maximum for
int32 boundaries if the user indicated the field is an
int32.

Also move to apd instead of ints.

Issue #56

Change-Id: I472c3c2b1fd8622430595bd062cef3bbd53b62f1
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2376
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/encoding/openapi/testdata/oneof.json b/encoding/openapi/testdata/oneof.json
index c526b28..ce39ad4 100644
--- a/encoding/openapi/testdata/oneof.json
+++ b/encoding/openapi/testdata/oneof.json
@@ -11,7 +11,8 @@
                   ],
                   "properties": {
                      "exact": {
-                        "type": "string"
+                        "type": "string",
+                        "format": "string"
                      }
                   }
                },
@@ -22,7 +23,8 @@
                   ],
                   "properties": {
                      "regex": {
-                        "type": "string"
+                        "type": "string",
+                        "format": "string"
                      }
                   }
                }