perf: add SIMD support for if-then-else kernels

[orlp]

All in all this results in the following speedups for when/then/otherwise compared to before we had the kernels on a Xeon Platinum 8481C:

mask%     0.20.10      branch             speedup
polars timings u8
0.00000   0.08115843   0.03505932         2.3x 
0.00100   0.03647457   0.01989060         1.8x             
0.01000   0.07882520   0.01981246         4.0x             
0.10000   0.41174116   0.01978657         20.8x            
0.50000   1.00037619   0.01942829         51.5x            
0.90000   0.39769651   0.01932436         20.6x            
0.99000   0.07776755   0.01975066         3.9x             
0.99900   0.03532240   0.01935847         1.8x             
1.00000   0.03219339   0.01969370         1.6x             
polars timings u8 (broadcast otherwise)        
0.00000   0.66645794   0.01661088         40.1x            
0.00100   0.66248909   0.01575884         42.0x            
0.01000   0.66174044   0.01577423         42.0x            
0.10000   0.66020744   0.01580585         41.8x            
0.50000   0.66131728   0.01591707         41.5x            
0.90000   0.65714505   0.01573395         41.8x            
0.99000   0.66128864   0.01575307         42.0x            
0.99900   0.66259916   0.01570407         42.2x            
1.00000   0.66125512   0.01576144         42.0x            
polars timings f64                             
0.00000   0.21898094   0.25657471         0.9x             
0.00100   0.20521458   0.25726009         0.8x             
0.01000   0.26828827   0.25833386         1.0x             
0.10000   0.52341402   0.25722402         2.0x             
0.50000   1.12231359   0.25894305         4.3x             
0.90000   0.51546188   0.25701572         2.0x             
0.99000   0.26381128   0.25602088         1.0x             
0.99900   0.20374866   0.25483548         0.8x             
1.00000   0.22121774   0.25552775         0.9x             
polars timings f64 (broadcast otherwise)       
0.00000   0.84157705   0.19835374         4.2x             
0.00100   0.88611176   0.19524437         4.5x             
0.01000   0.85838821   0.19667060         4.4x             
0.10000   0.98699411   0.19583061         5.0x             
0.50000   1.45492584   0.19726063         7.4x             
0.90000   0.92819551   0.19708807         4.7x             
0.99000   0.80215534   0.19600758         4.1x             
0.99900   0.79902379   0.19509045         4.1x             
1.00000   0.79653640   0.19531679         4.1x             
polars timings str                             
0.00000   0.81025074   0.40658252         2.0x             
0.00100   0.79277718   0.41019357         1.9x             
0.01000   0.90237664   0.47265907         1.9x             
0.10000   1.20691867   0.59651689         2.0x             
0.50000   1.75795868   0.82901697         2.1x             
0.90000   1.20894155   0.57644851         2.1x             
0.99000   0.92268797   0.47065160         2.0x             
0.99900   0.79767013   0.41163175         1.9x             
1.00000   0.81042450   0.40430602         2.0x             
polars timings str (broadcast otherwise)       
0.00000   2.13609492   0.28432058         7.5x             
0.00100   2.14303083   0.29062434         7.4x             
0.01000   2.21549710   0.34571675         6.4x             
0.10000   2.36127071   0.44268859         5.3x             
0.50000   2.31621091   0.40052368         5.8x             
0.90000   2.16956373   0.40142049         5.4x             
0.99000   2.14197054   0.40084098         5.3x             
0.99900   2.13997730   0.40132523         5.3x             
1.00000   2.14470416   0.39907459         5.4x             

[ritchie46]

That one's fast, in two ways. :D

[codecov]

Codecov Report

Attention: Patch coverage is 94.26752% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 81.18%. Comparing base (066c262) to head (379bd53).
Report is 11 commits behind head on main.

Files	Patch %	Lines
crates/polars-utils/src/cpuid.rs	57.14%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #15131      +/-   ##
==========================================
+ Coverage   81.08%   81.18%   +0.09%     
==========================================
  Files        1342     1347       +5     
  Lines      174150   175379    +1229     
  Branches     2459     2506      +47     
==========================================
+ Hits       141210   142381    +1171     
- Misses      32473    32519      +46     
- Partials      467      479      +12     

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