RFR: JDK-8299386: Refactor metaprogramming to use <type_traits>

[Justin King]

Cleanup `metaprogramming/` to just use implementations from `<type_traits>` that are available in C++11 and onward.

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Commit messages:
 - Add back missing template declaration
 - Refactor metaprogramming to use <type_traits>

Changes: https://git.openjdk.org/jdk/pull/11794/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11794&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299386
  Stats: 120 lines in 16 files changed: 11 ins; 69 del; 40 mod
  Patch: https://git.openjdk.org/jdk/pull/11794.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11794/head:pull/11794

PR: https://git.openjdk.org/jdk/pull/11794