This reverts commit af49af00.

Reason for revert: <INSERT REASONING HERE>

There is a mistake in codegen to cause error in snapshot.

Original change's description:
> PPC/s390: Fix arguement handling
> 
> 1. in AssembleMove and AssembleSwap, we need to distinguish Double and Float
> 2. in 32-bit mode, double needs to be counted as 2 slots in stack
> 
> R=​joransiu@ca.ibm.com, jbarboza@ca.ibm.com, michael_dawson@ca.ibm.com, mmallick@ca.ibm.com
> 
> Bug: 
> Change-Id: Iffe1844aa72e9d4c9492034c3df9a994e1304a27
> Reviewed-on: https://chromium-review.googlesource.com/720676
> Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
> Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
> Cr-Commit-Position: refs/heads/master@{#48593}

TBR=michael_dawson@ca.ibm.com,jyan@ca.ibm.com,joransiu@ca.ibm.com,jbarboza@ca.ibm.com,mmallick@ca.ibm.com

Change-Id: I76b7eb96e7bfc15e3d2b07474543e996b9ea5f86
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/721140Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#48600}