RFR(M): 7133857: exp() and pow() should use the x87 ISA on x86

[Vladimir Kozlov]

Looks good.

Vladimir

Roland Westrelin wrote:
> Implements Math.exp() and Math.pow() using the x87 ISA. It is based on an existing implementation in C2 that was disabled because it was found to be broken. This change fixes some corner cases of the previous implementation and uses the same code in the interpreter, c1 and c2 so that consistent results are obtained from exp() and pow().
> 
> http://cr.openjdk.java.net/~roland/7133857/webrev.00/
> 
> Roland.
>