RFR: JDK-8263261 Extend String::translateEscapes to support unicode escapes [v9]

[Jim Laskey]

> Currently String::translateEscapes does not support unicode escapes, reported as a IllegalArgumentException("Invalid escape sequence: ..."). String::translateEscapes should translate unicode escape sequences to provide full coverage,

Jim Laskey has updated the pull request incrementally with one additional commit since the last revision:

  Update String.java

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17491/files
  - new: https://git.openjdk.org/jdk/pull/17491/files/eba05c2d..8fd58b55

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17491&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17491&range=07-08

  Stats: 6 lines in 1 file changed: 3 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/17491.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17491/head:pull/17491

PR: https://git.openjdk.org/jdk/pull/17491