RFR (L) JDK-8195100: Use a low latency hashtable for SymbolTable

[Kim Barrett]

> On Aug 16, 2018, at 11:02 AM, coleen.phillimore at oracle.com wrote:
> 
> 
> This seems reasonable as a trivial fix.
> 
> There's also a bug https://bugs.openjdk.java.net/browse/JDK-8209138 which questions the history of making Symbol data u1.  It should just be char, I believe.

I’ve linked those two bugs, with a comment in 8209138, to help keep track of this.
Otherwise, fixing 8209138 without testing on arm/aarch64 might break the fix for
8209586 in the other direction.