RFR: 8300054: Use static_assert in basic_types_init

[Albert Mingkun Yang]

Simple change to use `static_assert` when applicable inside a function.

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Commit messages:
 - static-assert

Changes: https://git.openjdk.org/jdk/pull/11971/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11971&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300054
  Stats: 31 lines in 1 file changed: 0 ins; 0 del; 31 mod
  Patch: https://git.openjdk.org/jdk/pull/11971.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11971/head:pull/11971

PR: https://git.openjdk.org/jdk/pull/11971