Don't check an expression if it was checked cached

[ghost]

Fixes #22578

Sequel to #22491 -- checking for deferredNodes duplicates catches more than checking for deferredUnusedIdentifierNodes duplicates. Without the change to checkExpression, the new assertion would fire on several tests where nodes were checked multiple times.

[ghost]

@sandersn the test failure reduces to:

// @allowJs: true
// @checkJs: true
// @noEmit: true
// @filename: index.js
var c;
c = class { };
new c();

This error only happens in js. It looks like it's doing a non-cached check two times. I've looked through the callstack and can't find why this is js-specific.

[sandersn]

Binding might be a factor? Something like c = class {} might add a namespace meaning to c. Although I don't think it does unless the binder sees property assignments like c.p = {}.

[ghost]

Don't know why that was js-specific, but the problem was that getAssignedTypeOfBinaryExpression calls getTypeOfExpression which does a full check. Fixed by adding a CheckMode.JustType based on this comment:

Ideally, the entire family of checkXXX functions should have a parameter that indicates whether full error checking is required such that we can perform the optimizations locally.

[weswigham]

?

[weswigham]

I assume this fixes the assertion violation related to the related issues on RWC? (There are other rwc issues right now, but I only think one is related)

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