Handle overloaded constructors with mangled symbols in map generator

[tarek-y-ismail]

What's new?

Problem

When a public class has multiple constructor overloads, the symbols map generator emits a single wildcard glob (e.g. miral::Foo::Foo*;) to cover all of them. This has two drawbacks: the wildcard exports every overload under the same version stanza even when individual overloads were introduced in later releases, and quoted demangled names for constructors with nested template arguments (e.g. std::function<…>) are rendered differently by ld and lld, causing linker failures depending on the toolchain. Additionally, mangled symbols were incorrectly placed in the extern "C++" block of the map file rather than the top-level global: section where they belong.

Solution

For overloaded constructors, the generator now emits each constructor's individual mangled symbol instead of a wildcard glob, placing it in the global: section of the map file. To prevent duplicates when re-running the generator over an existing map, two new helpers are introduced: demangle_symbol (via c++filt) and is_symbol_covered_by_previous, which recognises whether a newly-generated mangled symbol is already represented by an existing entry — whether as an exact match, a C1/C2 constructor variant, or a matching quoted/wildcard demangled entry — and suppresses the duplicate accordingly.

How to test

Checklist

• Tests added and pass
• Adequate documentation added
• (optional) Added Screenshots or videos