RFR: 8310848: Convert ClassDesc and MethodTypeDesc to be stored in static final fields [v2]

[Chen Liang]

> This would encourage Classfile API users to use the descriptors as constants, which can improve performance by avoiding repeated validation and reusing cached descriptor strings for MethodTypeDesc. This patch updates usages in the main codebase and benchmarks; tests are left untouched.

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Fix build

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Changes:
  - all: https://git.openjdk.org/jdk/pull/14640/files
  - new: https://git.openjdk.org/jdk/pull/14640/files/3194e6b7..82442aac

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14640&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14640&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/14640.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14640/head:pull/14640

PR: https://git.openjdk.org/jdk/pull/14640