[mips64][ptr-compr] Switch to 31 bit Smis on 64-bit architectures

Port 12a9ee3a

Original Commit Message:

    32 bit Smis are incompatible with pointer compression so we land disable
    them before enabling pointer compression in order to separate memory and
    performance regressions caused by 31 bit Smis from pointer compression
    change.

Change-Id: I19647f18e7feafc6ca5b922c73785839ab528421
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1824306Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Yu Yin <xwafish@gmail.com>
Cr-Commit-Position: refs/heads/master@{#63960}

src/codegen/mips64/macro-assembler-mips64.cc

@@ -4284,7 +4284,6 @@ void TurboAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode,
 
 void TurboAssembler::LoadEntryFromBuiltinIndex(Register builtin_index) {
   STATIC_ASSERT(kSystemPointerSize == 8);
-  STATIC_ASSERT(kSmiShiftSize == 31);
   STATIC_ASSERT(kSmiTagSize == 1);
   STATIC_ASSERT(kSmiTag == 0);