Fix spammy -Winconsistent-override in HHVM

[mszabo-wikia]

Newer LLVM introduces -Winconsistent-override which is quite noisy for a few frequently-included headers in HHVM. Fix occurrences.

[meta-codesync]

@facebook-github-bot has imported this pull request. If you are a Meta employee, you can view this in D98724676. (Because this pull request was imported automatically, there will not be any future comments.)

[Wilfred]

FWIW this fails to build:

fbcode/hphp/runtime/ext/asio/ext_asio.cpp:174:59: error: 'override' specifier is not allowed outside a class definition
  174 | std::vector<std::string> AsioExtension::hackFiles() const override {
      |                                                           ^~~~~~~~
1 error generated.

[facebook-github-tools]

@mszabo-wikia has updated the pull request. You must reimport the pull request before landing.

[mszabo-wikia]

Right, should be definitions only - updated, thanks!