lower: generalise the *T-where-T-expected diagnostic to any pointer

The check only caught `for xs: (*m)` loop captures; passing a `*T`
parameter or any pointer local where `T` is expected still slipped through
to the LLVM verifier. Key the diagnostic on the lowered argument's type
instead of the capture, so a `*Move` parameter forwarded into a by-value
parameter is reported the same way. Ref-capture wording is preserved.

Add example 216 (pointer-parameter case) alongside 215 (loop capture).

tests/expected/216-pointer-param-value-arg-diagnostic.exit

@@ -0,0 +1 @@
+1