Prior to this commit, SpEL's Indexer incorrectly requested conversion
to wrappers instead of primitives when setting an element in a
primitive array.
This commit addresses this by requesting primitive conversion -- for
example, conversion to `int.class` instead of `Integer.class` when
setting a value in an `int[]` array.
For greater clarity, this commit also switches from using `TYPE`
constants in wrapper classes to primitive class literals -- for
example, from `Integer.TYPE` to `int.class`.
Closes gh-32147
62fa3f11c1