[10] RFR(S): 8183271: VectorizeDebug compiler directive command is broken

[Nils Eliasson]

Hi,

This change fixes the support for unsigned values in directives parsing. 
In bug 8170416: "CompilerControl: VectorizeDebug option type is 
incorrect" the support was added to the directives options, but not the 
parser.

Webrev: http://cr.openjdk.java.net/~neliasso/8183271/webrev.01/

Bug. https://bugs.openjdk.java.net/browse/JDK-8183271

Please review,

Nils Eliasson