110325: tree: make typeCheckSameTypedExprs order invariant for tuples r=msirek a=msirek

Type checking of CASE expressions (and other expressions handled by typeCheckSameTypedExprs) does not type check tuples properly because typeCheckSameTypedTupleExprs checking is only done when the tuple is the first expression in `exprs`.

This is fixed by finding the first tuple in `exprs`, searching the slice starting at index 0, and using that to drive typeCheckSameTypedExprs.

Fixes: #109105

Release note: None

Co-authored-by: Mark Sirek <[email protected]>