RFR (L) 8037210: Get rid of char-based descriptions 'J' of basic types

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8037210/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8037210
953 lines changed: 425 ins; 217 del; 311 mod

This is a massive cleanup of JSR292 code to replace char-based 
description of basic types by numeric constants.

Contributed-by: john.r.rose at oracle.com

Testing: jdk/java/{lang/invoke,util}, vm.mlvm.testlist, nashorn, jruby
Flags: -ea -esa -Xverify:all -D...COMPILE_THRESHOLD={0,30}

Best regards,
Vladimir Ivanov