RFR: 8255489: Unify the parsing of @lambda-proxy and @lambda-form-invokers tags in a classlist [v2]

[Calvin Cheung]

> With this change, the parsing of the `@lambda-proxy` and the `@lambda-form-invokers` tags in a classlist will be performed in the same function - `ClassListParser::parse_at_tags()`.
> 
> Also removing the `:` of the `@lambda-proxy:` to be consistent with the `@lambda-form-invokers `tag.
> 
> Ran tiers 1 through 4 tests successfully.

Calvin Cheung has updated the pull request incrementally with one additional commit since the last revision:

  improve the parsing code in ClassListParser::parse_at_tags()

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/942/files
  - new: https://git.openjdk.java.net/jdk/pull/942/files/6e8a0b2f..a3b75186

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=942&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=942&range=00-01

  Stats: 39 lines in 3 files changed: 18 ins; 8 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/942.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/942/head:pull/942

PR: https://git.openjdk.java.net/jdk/pull/942