RFR: 8243205: Modularize JVM flags declaration [v2]

[Ioi Lam]

> This is the first step for modularizing the xxx_globals.hpp. The goals are
> 
> - Improve modularization of HotSpot source
> - Reduce JVM build time
> 
> To prove that this works,  I have moved compiler_globals.hpp outside of the monolithic globals.hpp. Before this fix, compiler_globals.hpp was included by 922 HotSpot .o files. After this fix, it's included by 283 .o files.
> 
> I plan to do more refactoring later, such as:
> 
> - move gc_globals.hpp out of globals.hpp
> - move the flags related to tiered compilation (about 40 flags) out of globals.hpp
> - move the platform-specific flags outside of globals.hpp
>   - these flags should be used only by platform-specific files. They shouldn't be used by shared files.
> 
> Note: this is target for JDK 17.
> 
> Testing: I've tested tier1, builds-tier2, builds-tier3, builds-tier4 and builds-tier5 on mach5, plus locally building arm, aarch64, s390, ppc64, and zero.

Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:

  stefank comments

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1608/files
  - new: https://git.openjdk.java.net/jdk/pull/1608/files/dc277faf..6b922fb7

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1608&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1608&range=00-01

  Stats: 23 lines in 4 files changed: 2 ins; 2 del; 19 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1608.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1608/head:pull/1608

PR: https://git.openjdk.java.net/jdk/pull/1608