When we know a value passed to BytecodeArrayBuilder::LoadLiteral(double)
can be encoded as a Smi, we create LdaSmi instead of LdaConstant.

Driven by a forgotten Smi::FromInt() in BytecodeGenerator, also fixed in
this CL.

Bug: v8:11278
Change-Id: I4a1ad48e2c9aff8391113812e34dae838a1a38d3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2595437Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71827}