RFR: 8302795: Shared archive failed on old version class with jsr bytecode

[Calvin Cheung]

Please review this simple fix for avoid writing in to CDS archive during runtime while loading a shared old class (major_version < 50) with methods containg the jsr byte code.
Otherwise, JVM crashes with the following message in the hs err log:
`Error accessing class data sharing archive. Mapped file inaccessible during execution, possible disk/network problem.`

Passed tiers 1 - 4 testing.

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

Commit messages:
 - 8302795: Shared archive failed on old version class with jsr bytecode

Changes: https://git.openjdk.org/jdk/pull/12752/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12752&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302795
  Stats: 136 lines in 3 files changed: 135 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/12752.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12752/head:pull/12752

PR: https://git.openjdk.org/jdk/pull/12752