RFR: 8293051: Further refactor javac after removal of -source/-target/--release 7 [v2]

[Vicente Romero]

> This PR is a continuation of PR [1] which removed support for source and target 1.7 option in javac. This is is removing additional switches in javac that were providing support to legacy behavior related to source and target 1.7. What else could be missing?
> 
> TIA
> 
> [1] https://github.com/openjdk/jdk/pull/10074

Vicente Romero has updated the pull request incrementally with one additional commit since the last revision:

  fixing additional test

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10150/files
  - new: https://git.openjdk.org/jdk/pull/10150/files/331e4392..29f0b8a0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10150&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10150&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10150.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10150/head:pull/10150

PR: https://git.openjdk.org/jdk/pull/10150