RFR: 8341755: Optimize argNames in InnerClassLambdaMetafactory [v7]

[Shaojin Wen]

> A simple optimization that eliminates the allocation of the MethodTypeDescImpl object when parameterCount is equal to 0 and eliminates the allocation of argNames when parameterCount is equal to 1

Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:

  suggestion from @cl4es

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21399/files
  - new: https://git.openjdk.org/jdk/pull/21399/files/fc8b71ed..3d696618

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21399&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21399&range=05-06

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/21399.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21399/head:pull/21399

PR: https://git.openjdk.org/jdk/pull/21399