RFR: 8294591: Fix cast-function-type warning in TemplateTable [v2]

[Aleksey Shipilev]

> After [JDK-8294314](https://bugs.openjdk.org/browse/JDK-8294314), we would have `templateTable.cpp` excluded with cast-function-type warning. The underlying cause for it is casting functions for `ldc` bytecodes, which take `bool`-typed handlers:

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Also disable warnings in gtests

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10493/files
  - new: https://git.openjdk.org/jdk/pull/10493/files/9be451ad..3f310c8e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10493&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10493&range=00-01

  Stats: 3 lines in 1 file changed: 3 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10493.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10493/head:pull/10493

PR: https://git.openjdk.org/jdk/pull/10493