[AMDGPU] Remove obsolete hack from allowsMisalignedMemoryAccesses. NFCI.

[foad]

Typo in summary "from allowsMisalignedMemoryAccesses" (not Impl).

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

if (IsFast)
     *IsFast = true;
 
   return Size >= 32 && Alignment >= Align(4);
 }
 
 bool SITargetLowering::allowsMisalignedMemoryAccesses(
     EVT VT, unsigned AddrSpace, Align Alignment, MachineMemOperand::Flags Flags,
     bool *IsFast) const {
-  if (IsFast)
-    *IsFast = false;
-
-  // TODO: I think v3i32 should allow unaligned accesses on CI with DS_READ_B96,
-  // which isn't a simple VT.
-  // Until MVT is extended to handle this, simply check for the size and
-  // rely on the condition below: allow accesses if the size is a multiple of 4.
-  if (VT == MVT::Other || (VT != MVT::Other && VT.getSizeInBits() > 1024 &&
-                           VT.getStoreSize() > 16)) {
-    return false;
-  }
-
   bool Allow = allowsMisalignedMemoryAccessesImpl(VT.getSizeInBits(), AddrSpace,
                                                   Alignment, Flags, IsFast);
 
   if (Allow && IsFast && Subtarget->hasUnalignedDSAccessEnabled() &&
       (AddrSpace == AMDGPUAS::LOCAL_ADDRESS ||
        AddrSpace == AMDGPUAS::REGION_ADDRESS)) {
     // Lie it is fast if +unaligned-access-mode is passed so that DS accesses
     // get vectorized. We could use ds_read2_b*/ds_write2_b* instructions on a