[RISC-V] De-intrinsify Min/MaxMagnitude

[tomeksowi]

Fallback to the library version, the generated version returned the lesser/greater magnitude instead of the original argument with such.

Also adjust Min/Max(Number) routines to adhere to new NaN requirements in #119897

Part of #84834, cc @dotnet/samsung

[dotnet-policy-service]

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[tomeksowi]

@risc-vv /run

[risc-vv]

RISC-V pull_request-CLR-QEMU: 9101 / 9131 (99.67%)

=======================
      passed: 9101
      failed: 2
     skipped: 591
      killed: 28
------------------------
 TOTAL tests: 9722
VIRTUAL time: 80h 42min 24s 237ms
   REAL time: 1h 19min 1s 481ms
=======================

report.xml, report.md, failures.xml, testclr_details.tar.zst

RISC-V pull_request-CLR-VF2: 9101 / 9131 (99.67%)

=======================
      passed: 9101
      failed: 2
     skipped: 591
      killed: 28
------------------------
 TOTAL tests: 9722
VIRTUAL time: 32h 0min 35s 150ms
   REAL time: 2h 7min 10s 321ms
=======================

report.xml, report.md, failures.xml, testclr_details.tar.zst

RISC-V pull_request-FX-QEMU: 0 / 1 (0.00%)

=======================
      passed: 0
      failed: 0
     skipped: 14
      killed: 1
------------------------
 TOTAL tests: 15
VIRTUAL time: 15s 444ms
   REAL time: 4h 30min 0s 487ms
=======================

report.xml, report.md, failures.xml, testclr_details.tar.zst

RISC-V pull_request-FX-VF2: 0 / 66 (0.00%)

=======================
      passed: 0
      failed: 0
     skipped: 14
      killed: 66
------------------------
 TOTAL tests: 80
VIRTUAL time: 1min 14s 522ms
   REAL time: 12h 30min 7s 384ms
=======================

report.xml, report.md, failures.xml, testclr_details.tar.zst

Build information and commands

GIT: 0d012b4d1be3ca4ebd5e3600f19920d644db105b
CI: d023c7d591ab286aa343d644f00b5daa59d8d6b0
REPO: dotnet/runtime
BRANCH: main
CONFIG: Checked
LIB_CONFIG: Release

[JulieLeeMSFT]

@tannergooding and @jakobbotsch, please review this PR.

[tannergooding]

Thanks! Will let @jakobbotsch give it another pass as well, but I think this looks good to merge