Bug 1791961 - Re-enable C++20 -Wambiguous-reversed-operator warnings. r=firefox-build-system-reviewers,glandium

clang only reports these warnings when compiling with -std=c++20.

Depends on D179025

Differential Revision: https://phabricator.services.mozilla.com/D179026

build/moz.configure/warnings.configure

@@ -106,7 +106,6 @@ check_and_add_warning("-Wvolatile", cxx_compiler)
 
 # Downgrade some C++20 warnings-as-errors to warnings that we can fix after we
 # compile as C++20 (bug 1768116). They don't need to block upgrading to C++20.
-check_and_add_warning("-Wno-ambiguous-reversed-operator", cxx_compiler)
 check_and_add_warning("-Wno-error=deprecated", cxx_compiler)
 check_and_add_warning("-Wno-error=deprecated-anon-enum-enum-conversion", cxx_compiler)
 check_and_add_warning("-Wno-error=deprecated-enum-enum-conversion", cxx_compiler)