Besides, enable float support on simulator.

Port commit 098f31f4
Port commit a6da8161

As defined in
https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html#_procedure_calling_convention
Loongarch calling convention uses GP to pass floating-point
arguments when no FP is available.

Bug: v8:12614, chromium:1052746

Change-Id: I33d4115674604604b2b7e9178a306efb6000222b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3448195Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Yu Liu <liuyu@loongson.cn>
Auto-Submit: Yu Liu <liuyu@loongson.cn>
Cr-Commit-Position: refs/heads/main@{#80062}