RFR: 8266497: Remove unnecessary EMCP liveness indication

[Coleen Phillimore]

Marking running_emcp for Method* is unnecessary.  We can set/clear breakpoints in all old emcp methods because they're not deallocated until none are running.  See longer explanation in the CR.

Tested with tier1-6, tiers 7,8 are running and 98% passing.

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Commit messages:
 - 8266497: Remove unnecessary EMCP liveness indication

Changes: https://git.openjdk.java.net/jdk/pull/3852/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3852&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266497
  Stats: 78 lines in 4 files changed: 9 ins; 64 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3852.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3852/head:pull/3852

PR: https://git.openjdk.java.net/jdk/pull/3852