Raspberry Pi Pico RP2040 CoreMark

```
2K performance run parameters for coremark.
CoreMark Size : 666
Total ticks : 19091876
Total time (secs): 19.091876
Iterations/Sec : 157.134899
Iterations : 3000
Compiler version : GCC9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599]
Compiler flags : -O3 -Wall -Wextra
Memory location : STACK
seedcrc : 0xe9f5
[0]crclist : 0xe714
[0]crcmatrix : 0x1fd7
[0]crcstate : 0x8e3a
[0]crcfinal : 0xcc42
Correct operation validated. See README.md for run and reporting rules.
CoreMark 1.0 : 157.134899 / GCC9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599] -O3 -Wall -Wextra / STACK
```

Runs in RAM by default, system frequency 125MHz, test results are affected by multiple factors.

https://github.com/nickfox-taterli/pico-coremark