RFR(S): 8213419: C2 may hang in MulLNode::Ideal()/MulINode::Ideal() with gcc 8.2.1

[Roland Westrelin]

Hi Dean,

> jint abs_con = uabs(con);
>
>
> if the unsigned value is too big to fit in a signed int?

Yes, you must be right. So move all computations to unsigned:

http://cr.openjdk.java.net/~roland/8213419/webrev.01/

?

Roland.