RFR: JDK-8285932 Implementation of JEP-430 String Templates (Preview) [v5]

[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 two additional commits since the last revision:

 - Requested changes #2
 - Requested changes

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10889/files
  - new: https://git.openjdk.org/jdk/pull/10889/files/347df715..d30e6eff

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10889&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10889&range=03-04

  Stats: 168 lines in 15 files changed: 60 ins; 60 del; 48 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