jmx-dev RFR: JDK-8348574 : Simplify c1/c2_globals inclusions

[Suchismith Roy]

JBS Issue : [JDK-8348574](https://bugs.openjdk.org/browse/JDK-8348574)

c1_globals.hpp includes c1_globals_pd.hpp. c1_globals_pd.hpp includes the corresponding CPU_HEADER and OS_HEADER files. All of the c1_globals_<os>.hpp files are essentially identical and basically empty. (They just include globalDefinitions.hpp and macros.hpp, and provide nothing additional.)

This could be simplified by having c1_globals.hpp do the CPU_HEADER inclusion directly, and remove c1_globals_pd.hpp and all c1_globals_<os>.hpp files.

Even if there are some non-vacuous c1_globals_<os>.hpp files in the future, c1_globals_pd.hpp seems unwarranted; just add the OS_HEADER include directly in c1_globals.hpp. The c1_globals_pd.hpp files really don't seem worth the extra indirection.

Similarly for c2_globals.hpp &etc.

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Commit messages:
 - Update c2_globals.hpp
 - c1 header
 - global headers

Changes: https://git.openjdk.org/jdk/pull/25773/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25773&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348574
  Stats: 366 lines in 13 files changed: 2 ins; 360 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/25773.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25773/head:pull/25773

PR: https://git.openjdk.org/jdk/pull/25773