RFR: 8294982: Implementation of Classfile API [v55]

[Adam Sotona]

> This is root pull request with Classfile API implementation, tests and benchmarks initial drop into JDK.
> 
> Following pull requests consolidating JDK class files parsing, generating, and transforming ([JDK-8294957](https://bugs.openjdk.org/browse/JDK-8294957)) will chain to this one.
> 
> Classfile API development is tracked at:
> https://github.com/openjdk/jdk-sandbox/tree/classfile-api-branch
> 
> Development branch of consolidated JDK class files parsing, generating, and transforming is at:
> https://github.com/openjdk/jdk-sandbox/tree/classfile-api-dev-branch
> 
> Classfile API [JEP](https://bugs.openjdk.org/browse/JDK-8280389) and [online API documentation](https://htmlpreview.github.io/?https://raw.githubusercontent.com/openjdk/jdk-sandbox/classfile-api-javadoc-branch/doc/classfile-api/javadoc/java.base/jdk/internal/classfile/package-summary.html) is also available.
> 
> Please take you time to review this non-trivial JDK addition.
> 
> Thank you,
> Adam

Adam Sotona has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 183 commits:

 - Merge branch 'master' into JDK-8294982
 - fixed new lines at end of file
 - package jdk.internal.classfile.jdktypes moved to jdk.internal.classfile.java.lang.constant
 - fixed CodeRelabeler javadoc
 - Shared `toString` formats for bound and unbound instructions
 - generic implementation of ResolvedTransform
 - snippets and tests synced with jdk.jfr class instrumentation source code
 - simplified initialization of terminal builder in chained builders
 - simplified CodeImpl.SINGLETON_INSTRUCTIONS initialization
 - fixed handling of array descriptors by Util::toInternalName
 - ... and 173 more: https://git.openjdk.org/jdk/compare/45a616a8...4680572a

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Changes: https://git.openjdk.org/jdk/pull/10982/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10982&range=54
  Stats: 53052 lines in 322 files changed: 53048 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/10982.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10982/head:pull/10982

PR: https://git.openjdk.org/jdk/pull/10982