RFR: 8265103: Remove unnecessary inclusion of oopMap.hpp

[Ioi Lam]

oopMap.hpp is included by about 585 out of about 1000 .o files in HotSpot. In turn, it pulls in other complex headers such as vmreg.hpp, register.hpp and their cpu-dependent headers.

There are only 4 header files that include oopMap.hpp. All of these can be replaced for forward declarations.

According to https://github.com/iklam/tools/tree/main/headers


[before]

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Commit messages:
 - fixed copyright year
 - removed unrelated changes
 - 8265103: Remove unnecessary inclusion of oopMap.hpp

Changes: https://git.openjdk.java.net/jdk/pull/3446/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3446&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265103
  Stats: 75 lines in 53 files changed: 58 ins; 4 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3446.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3446/head:pull/3446

PR: https://git.openjdk.java.net/jdk/pull/3446