[clang] Fix copy constructor of CompilerInvocation

The `CompilerInvocationBase` class factors out members of `CompilerInvocation` that need special handling (initialization or copy constructor), so that `CompilerInvocation` can be implemented as a simple value object.

Currently, the `AnalyzerOpts` member of `CompilerInvocation` violates that setup. This patch extracts the member to `CompilerInvocationBase` and handles it in the copy constructor the same way other it handles other members.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D99568