cmd/compile: fix load int32 to FP register on big-endian MIPS64
cmd/compile: fix load int32 to FP register on big-endian MIPS64

Fixes #16903.

Change-Id: I1f6fcd57e14b2b62e208b7bb3adccd5fd7f8bdbc
Reviewed-on: https://go-review.googlesource.com/27933
Run-TryBot: Cherry Zhang <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Minux Ma <72d850dbd8858b791995463d8539b5a379577f28@golang.org>

akutz/go,goodlang/good,codestation/go,suncycheng/go,linux-on-ibm-z/go,derekmarcotte/go,akutz/go,polyverse-security/go,goodlang/good,goodlang/good,cloudflare/go,momchil-velikov/go,Cofyc/go,derekmarcotte/go,suncycheng/go,Cofyc/go,cloudflare/go,cloudflare/go,josharian/go,nawawi/go,suncycheng/go,josharian/go,golang/go,polyverse-security/go,vsekhar/elastic-go,goodlang/good,josharian/go,momchil-velikov/go,nawawi/go,codestation/go,christopher-henderson/Go,ImJasonH/go,linux-on-ibm-z/go,vsekhar/elastic-go,CAFxX/go,CAFxX/go,golang/go,momchil-velikov/go,linux-on-ibm-z/go,derekmarcotte/go,akutz/go,vsekhar/elastic-go,linux-on-ibm-z/go,Cofyc/go,Cofyc/go,vsekhar/elastic-go,akutz/go,codestation/go,goodlang/good,momchil-velikov/go,golang/go,goodlang/good,momchil-velikov/go,CAFxX/go,akutz/go,linux-on-ibm-z/go,cloudflare/go,derekmarcotte/go,suncycheng/go,golang/go,momchil-velikov/go,linux-on-ibm-z/go,suncycheng/go,goodlang/good,Cofyc/go,golang/go,Cofyc/go,CAFxX/go,CAFxX/go,linux-on-ibm-z/go,polyverse-security/go,CAFxX/go,cloudflare/go,nawawi/go,Cofyc/go,derekmarcotte/go,CAFxX/go,derekmarcotte/go,nawawi/go,golang/go,vsekhar/elastic-go,josharian/go,nawawi/go,goodlang/good,ImJasonH/go,CAFxX/go,polyverse-security/go,cloudflare/go,polyverse-security/go,derekmarcotte/go,golang/go,akutz/go,ImJasonH/go,cloudflare/go,ImJasonH/go,linux-on-ibm-z/go,codestation/go,polyverse-security/go,polyverse-security/go,nawawi/go,akutz/go,cloudflare/go,momchil-velikov/go,ImJasonH/go,vsekhar/elastic-go,codestation/go,ImJasonH/go,josharian/go,josharian/go,suncycheng/go,josharian/go,suncycheng/go,polyverse-security/go,akutz/go,suncycheng/go,nawawi/go,ImJasonH/go,nawawi/go,momchil-velikov/go,Cofyc/go,josharian/go,derekmarcotte/go,codestation/go,vsekhar/elastic-go,codestation/go,golang/go,codestation/go,ImJasonH/go,vsekhar/elastic-go