RFR: 8271820: Implementation of JEP 416: Reimplement Core Reflection with Method Handle

[Mandy Chung]

This reimplements core reflection with method handles.

For `Constructor::newInstance` and `Method::invoke`, the new implementation uses `MethodHandle`.  For `Field` accessor, the new implementation uses `VarHandle`.    For the first few invocations of one of these reflective methods on a specific reflective object we invoke the corresponding method handle directly. After that we spin a dynamic bytecode stub defined in a hidden class which loads the target `MethodHandle` or `VarHandle` from its class data as a dynamically computed constant. Loading the method handle from a constant allows JIT to inline the method-handle invocation in order to achieve good performance.

The VM's native reflection methods are needed during early startup, before the method-handle mechanism is initialized. That happens soon after System::initPhase1 and before System::initPhase2, after which we switch to using method handles exclusively.

The core reflection and method handle implementation are updated to handle chained caller-sensitive method calls [1] properly. A caller-sensitive method can define with a caller-sensitive adapter method that will take an additional caller class parameter and the adapter method will be annotated with `@CallerSensitiveAdapter` for better auditing.   See the detailed description from [2].

Ran tier1-tier8 tests.   

[1] https://bugs.openjdk.java.net/browse/JDK-8013527
[2] https://bugs.openjdk.java.net/browse/JDK-8271820?focusedCommentId=14439430&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14439430

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Commit messages:
 - fix whitespace
 - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke
 - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke
 - Merge
 - clean up test
 - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke
 - cleanup
 - Merge branch 'master' of https://github.com/openjdk/jdk into reimplement-method-invoke
 - fix ClassByteBuilder to handle short field type properly. Support volatile fields
 - minor cleanup
 - ... and 5 more: https://git.openjdk.java.net/jdk/compare/cb368802...c575c3db

Changes: https://git.openjdk.java.net/jdk/pull/5027/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5027&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271820
  Stats: 7572 lines in 75 files changed: 7103 ins; 288 del; 181 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5027.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5027/head:pull/5027

PR: https://git.openjdk.java.net/jdk/pull/5027