RFR: JDK-8285932 Implementation of JEP 430 String Templates (Preview) [v22]

[Jim Laskey]

> Enhance the Java programming language with string templates, which are similar to string literals but contain embedded expressions. A string template is interpreted at run time by replacing each expression with the result of evaluating that expression, possibly after further validation and transformation. This is a [preview language feature and API](http://openjdk.java.net/jeps/12).

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

  Requested changes #8

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10889/files
  - new: https://git.openjdk.org/jdk/pull/10889/files/e4812ee5..dcceb671

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10889&range=21
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10889&range=20-21

  Stats: 231 lines in 13 files changed: 32 ins; 113 del; 86 mod
  Patch: https://git.openjdk.org/jdk/pull/10889.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10889/head:pull/10889

PR: https://git.openjdk.org/jdk/pull/10889