Fix a compilation issue present in Xcode 16 beta

[matux]

Description of the change

This PR fixes a compilation issue in RollbarCrashMonitor_CPPException.cpp where the symbols std::terminate_handler and std::set_terminate used in the source weren't being found by the compiler.

Libc++ is in the process of splitting larger headers into smaller modular headers. Previous to Libc++ 20, the smaller modular headers were being included transitively to avoid breaking existing code. In this case, exception was a transitive include of typeinfo.

To ease the removal of transitive includes in libc++, libc++ will remove unnecessary transitive includes in newly supported C++ versions. This means that users will have to fix their missing includes in order to upgrade to a newer version of the Standard. Libc++ also reserves the right to remove transitive includes at any other time, however new language versions will be used as a convenient way to perform bulk removals of transitive includes.

More info: https://libcxx.llvm.org/DesignDocs/HeaderRemovalPolicy.html

This affects the new Xcode 16 which is currently in Beta 3.

Contribution by @dongdong945

@dongdong945 had previously contributed a fix for this in #347 (thank you!).

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

• Fixes Rollbar won't compile for a Swift Mac OS app #348
• SDK-365