expression: implement vectorized evaluation for builtinCastRealAsRealSig

[hellojujian]

What problem does this PR solve?

implement vectorized evaluation for builtinCastRealAsRealSig, for #12105

What is changed and how it works?

according to benchmark, about 10 times faster than before:

BenchmarkVectorizedBuiltinCastFunc/builtinCastRealAsRealSig-VecBuiltinFunc-8       	 1000000	      1826 ns/op	       0 B/op	       0 allocs/op
BenchmarkVectorizedBuiltinCastFunc/builtinCastRealAsRealSig-NonVecBuiltinFunc-8    	  100000	     20722 ns/op	       0 B/op	       0 allocs/op

Check List

Tests

• Unit test

[CLAassistant]

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1 out of 2 committers have signed the CLA.

✅ hellojujian
❌ jujian

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[codecov]

Codecov Report

Merging #12280 into master will decrease coverage by 0.1224%.
The diff coverage is 85.7142%.

@@               Coverage Diff                @@
##             master     #12280        +/-   ##
================================================
- Coverage   81.2062%   81.0837%   -0.1225%     
================================================
  Files           454        454                
  Lines         99448      98672       -776     
================================================
- Hits          80758      80007       -751     
  Misses        12894      12894                
+ Partials       5796       5771        -25

[hellojujian]

wrong git config failed CLA check :(
close and create a new PR