Upstreaming: BaseTypeValidator change

[wmdietl]

https://github.com/jspecify/checker-framework/blame/2eea6f8242391624def3818289abc44c1ec4ae0b/framework/src/main/java/org/checkerframework/common/basetype/BaseTypeValidator.java#L562

This ignores parts of the checks in visitParameterizedType and notes that the check seems weird.

Steps:

• investigate whether the EISOP behavior makes sense or needs adjusting,
• investigate what different behavior the jspecify-reference-checker needs,
• address by either adjusting upstream in general or adding a new helper method to allow downstream adjustment.