[RFR] 8241680: KeyPairGen & Signature microbenchmarks need updating for disabled EC curves

[Anthony Scarpino]

Hi,

I need a quick code review of updates to the microbenchmarks tests for 
EC.  These tests used curves that are now disabled by default in 15.

https://cr.openjdk.java.net/~ascarpino/8241680/webrev/

thanks

Tony