cmd/compile: remove 8-byte alignment requirement of stack slot on mips64

This CL applies CL 267999 to mips64.

Updates #42385

Change-Id: Ideab21be0d8c1a36b3be7411b24adac70a3d16e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/297771
Reviewed-by: eric fang <eric.fang@arm.com>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: eric fang <eric.fang@arm.com>
Run-TryBot: eric fang <eric.fang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/src/cmd/compile/internal/ssagen/pgen.go b/src/cmd/compile/internal/ssagen/pgen.go
index 25b09e1..717f111 100644
--- a/src/cmd/compile/internal/ssagen/pgen.go
+++ b/src/cmd/compile/internal/ssagen/pgen.go
@@ -138,7 +138,7 @@
 		} else {
 			lastHasPtr = false
 		}
-		if Arch.LinkArch.InFamily(sys.MIPS, sys.MIPS64, sys.ARM, sys.ARM64, sys.PPC64, sys.S390X) {
+		if Arch.LinkArch.InFamily(sys.MIPS, sys.ARM, sys.ARM64, sys.PPC64, sys.S390X) {
 			s.stksize = types.Rnd(s.stksize, int64(types.PtrSize))
 		}
 		n.SetFrameOffset(-s.stksize)