RFR: 8256538: Fix annoying awk warning in configure for java versions [v2]

[Magnus Ihse Bursie]

> The change from grep to awk in JDK-8244248 and further bug fixed in JDK-8244756 still has invalid syntax. This causes some awk (most notably gawk, the most commonly used) to complain:
> 
> gawk: cmd. line:1: warning: regexp escape sequence `"' is not a known regexp operator
> 
> This is annoying and should be fixed.

Magnus Ihse Bursie has updated the pull request incrementally with one additional commit since the last revision:

  Also fix bad code as copied in BOOTJDK_CHECK_BUILD_JDK

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1285/files
  - new: https://git.openjdk.java.net/jdk/pull/1285/files/9d5fd4fc..842287e0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1285&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1285&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1285.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1285/head:pull/1285

PR: https://git.openjdk.java.net/jdk/pull/1285