Fix recursive mapped type infinite recursion

[sandersn]

Fixes #17847

isGenericMappedType indirectly calls getResolvedBaseConstraint, but is called indirectly from inside getResolvedBaseConstraint. This avoids the circularity check in getResolvedBaseConstraint, which causes an infinite recursion for certain malformed types.

Interestingly, I found four approaches that fixed the bug:

1. Delete lines 6559-6561 (if (isGenericMappedType(t)) { return emptyObjectType; })
2. Pass typeStack to isGenericMappedType and check it in getConstraintOfTypeParameter instead of calling hasNonCircularBaseConstraint.
3. Clone isGenericMappedType and its callees into getResolvedBaseConstraint (and check typeStack).
4. Clone isGenericMappedType and its callees into getResolvedBaseConstraint, and merge into a single function (that checks typeStack).

And @weswigham suggested a fifth,

5. Remove typeStack and use push/popTypeResolution instead.

Previously, I decided on (2) because it avoids forking the code paths, but (5) reuses code even better.

[sandersn]

@weswigham, I got push/popTypeResolution to work by making circularConstraintType behave the same way as undefined, since it should. I think this change is ready to go.