RFR(XXS): 8034775: Failing to initialize VM when running with negative value for -XX:CICompilerCount

[Albert]

Hi,

could I get reviews for this small patch?

bug: https://bugs.openjdk.java.net/browse/JDK-8034775
webrev: http://cr.openjdk.java.net/~anoll/8034775/webrev.00/

With this patch, we check at VM startup for a reasonable minimal number 
of compiler
threads (1 for non-tiered, and 2 for tiered). If this minimum is not 
reached, the VM exits.

Added regression test.

Many thanks,
Albert