8164738: Convert AltHashing_test to GTest
Reviewed-by: dholmes, coleenp

8033792: AltHashing used jint for imprecise bit shifting
Summary: AltHashing used jint the way of juint in bit shifting which could lead loss of precision. Fix by change _seed defined as juint.
Reviewed-by: coleenp, ccheung
Contributed-by: yumin.qi@oracle.com

7158800: Improve storage of symbol tables
Summary: Use an alternate version of hashing algorithm for symbol string tables and after a certain bucket size to improve performance
Reviewed-by: pbk, kamg, dlong, kvn, fparain