RFR: 8261480: MetaspaceShared::preload_and_dump should check exceptions

[Ioi Lam]

`MetaspaceShared::preload_and_dump()`, as well as many of the functions that it calls, have extensive use of `THREAD` when calling functions that can potentially throw exceptions. Many of these call sites explicitly check for failure status, or assume that the caller would terminate the VM if an exception were to happen. This makes the code hard to understand and potentially unsafe.

I have make 3 types of changes:

1. In most cases, replace THREAD with CHECK. Moved all the fatal error check to `MetaspaceShared::preload_and_dump()`, where it handles any uncaught exceptions and explicitly terminates the VM.
2. If a `TRAPS` function can never throw, replace the `TRAPS` declaration with `Thread* current`
3. In cases where an exception is handled and discarded, use `THREAD` immediately followed by  `HAS_PENDING_EXCEPTION` -> `CLEAR_PENDING_EXCEPTION` to make the code easy to understand. HandleMark is used to assert that no exception escapes.

(See `MetaspaceShared::try_link_class` for an example of 2 and 3).

Tested with tiers 1-4.

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Commit messages:
 - added ExceptionMark
 - Merge branch 'master' into 8261480-preload-and-dump-should-check-exceptions
 - step3
 - step2
 - 8261480: MetaspaceShared::preload_and_dump should check exceptions

Changes: https://git.openjdk.java.net/jdk/pull/2925/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2925&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261480
  Stats: 413 lines in 13 files changed: 151 ins; 156 del; 106 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2925.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2925/head:pull/2925

PR: https://git.openjdk.java.net/jdk/pull/2925