RFR: 8312401: SymbolTable::do_add_if_needed hang when requesting length exceeds max_symbol_length [v3]

[Jiangli Zhou]

> Please review the simple fix to resolve infinite loop in SymbolTable::do_add_if_needed caused by extra long symbol string that exceeds Symbol::max_length(). See JDK-8312401 for details.
> 
> The jtreg test is converted from a test case constructed by @cushon.

Jiangli Zhou has updated the pull request incrementally with one additional commit since the last revision:

  Revert the change that truncates the string in String::as_symbol.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/14938/files
  - new: https://git.openjdk.org/jdk/pull/14938/files/19a7d3d4..5ee367bf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14938&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14938&range=01-02

  Stats: 15 lines in 2 files changed: 0 ins; 15 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/14938.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14938/head:pull/14938

PR: https://git.openjdk.org/jdk/pull/14938