RFR: 8323801: <s> tag doesn't strikethrough the text [v2]

[Alexey Ivanov]

> When `<s>` tag is used inside `<u>`, the `line-through` style is lost, and the text is rendered with `underline` only. However, if `<strike>` is used, the text is rendered with both `underline` and `line-through` styles.
> 
> Both `<s>` and `<strike>` should render the text the same way.

Alexey Ivanov has updated the pull request incrementally with three additional commits since the last revision:

 - Use RuntimeException rather than Error
 - Rename the Java class to HTMLUnderlineStrike
 - Rename HTMLStrike.java to HTMLUnderlineStrike.java

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17659/files
  - new: https://git.openjdk.org/jdk/pull/17659/files/9eae36d4..d4c97600

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17659&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17659&range=00-01

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/17659.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17659/head:pull/17659

PR: https://git.openjdk.org/jdk/pull/17659