[jsc-dev] Some easy patch for review for baseline && DFG

[Benjamin Poulain]

Hi all,

I have some simple patches for review:
     https://bugs.webkit.org/show_bug.cgi?id=155063 - [JSC] Simplify the 
overflow check of ArithAbs
     https://bugs.webkit.org/show_bug.cgi?id=155071 - [JSC] Remove a 
useless "Move" from baseline-JIT op_mul's fast path
     https://bugs.webkit.org/show_bug.cgi?id=155082 - [JSC] Use 3 
operands Add in more places

They are targeting simple issues in the lower tiers.

Benjamin