perf: Simple optimization

[hansl]

Prior to this change, a lot of assignments defaulted to something like Move SRC, TMP; PushRegister TMP. With TMP being a temporary register. These are redundant as we could simple PushRegister SRC. This change removes those duplicated temporary registers.

Another part of this change is removing the temporary register when building an array literal; each non-spread elements were assigned to a temp register instead of directly being pushed on the array.

Both changes are improving the benchmarks by about 1-4%.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	53,125	53,125	0
Passed	51,051	51,051	0
Ignored	1,482	1,482	0
Failed	592	592	0
Panics	0	0	0
Conformance	96.10%	96.10%	0.00%

Tested main commit: 8820b77750be087bff9448e6091baec9c8490f58
Tested PR commit: ae6fac4f2ad39f51eac1675ea53732a263b63049
Compare commits: 8820b77...ae6fac4

[codecov]

Codecov Report

❌ Patch coverage is 52.38095% with 20 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.86%. Comparing base (6ddc2b4) to head (ae6fac4).
⚠️ Report is 963 commits behind head on main.

Files with missing lines	Patch %	Lines
core/engine/src/bytecompiler/mod.rs	45.00%	11 Missing ⚠️
core/engine/src/bytecompiler/expression/mod.rs	59.09%	9 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #5356       +/-   ##
===========================================
+ Coverage   47.24%   59.86%   +12.62%     
===========================================
  Files         476      566       +90     
  Lines       46892    62929    +16037     
===========================================
+ Hits        22154    37674    +15520     
- Misses      24738    25255      +517     

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