RFR: 8260471: Change SystemDictionary::X_klass calls to vmClasses::X_klass

[Ioi Lam]

This is the second step of https://github.com/openjdk/jdk/pull/2246 (8260467: Move well-known classes from systemDictionary.hpp to vmClasses.hpp). These are mostly boiler-plate changes done by scripts.

[1]  Change calls like 

SystemDictionary::Object_klass()
SystemDictionary::Throwable_klass_is_loaded()
SystemDictionary::box_klass_type()

to 

vmClasses::Object_klass()
vmClasses::Throwable_klass_is_loaded()
vmClasses::box_klass_type()

[2] Remove unnecessary inclusion of systemDictionary.hpp (replace with vmClasses.hpp if necessary). In some cases, I have to add signature.hpp to some files, which only indirectly included signature.hpp through systemDictionary.hpp.

[3] In the previous PR, I incorrectly used the enum name `VMClassID`. This PR changes it to `vmClassID` to match the existing use of `vmSymbolID` and `vmIntrinsicID`.

Due to the refactoring of these two PRs, the number of HotSpot .o files that include systemDictionary.hpp decreases from 491 to 91. HotSpot build time is reduced by about 2%

Tested with mach5: tier1, builds-tier2, builds-tier3, builds-tier4 and builds-tier5. Also locally: aarch64, arm, ppc64, s390, x86, and zero.

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Commit messages:
 - 8260471: Change SystemDictionary::xxx_klass() calls to vmClasses::xxx_klass()

Changes: https://git.openjdk.java.net/jdk/pull/2301/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2301&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260471
  Stats: 691 lines in 185 files changed: 85 ins; 64 del; 542 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2301.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2301/head:pull/2301

PR: https://git.openjdk.java.net/jdk/pull/2301