[JIT] On importing a CEE_INITOBJ for a simd, construct a VecCon(0) (#81982)
* On importing a CEE_INITOBJ for a simd, construct a VecCon(0) of that type
* Formatting
* Check layout to determine if type is a SIMD to avoid redundant impNormStructType call
* Fix assert
* Remove assert
* Update src/coreclr/jit/importer.cpp
Co-authored-by: SingleAccretion <62474226+SingleAccretion@users.noreply.github.com>
* Update importer.cpp
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Co-authored-by: SingleAccretion <62474226+SingleAccretion@users.noreply.github.com>