Bug 22126 – -checkaction=context should not print overlapped struct members

Reduced test case: ``` struct S { union { double num; immutable(char)[] name; } } void main() { assert(S.init != S.init); } ``` Compiling with -checkaction=context gives: core.exception.OutOfMemoryError@src/core/exception.d(647): Memory allocation failed ---------------- The problem is that the double 'num' overlaps the length field of 'name', and double.nan interpreted as a length is 0x7FF8000000000000, so it's no wonder Memory allocation failed. formatMembers in core/internal/dassert.d should not naively iterate over .tupleof but watch for overlapped fields.

@MoonlightSentinel created dlang/druntime pull request #3522 "Fix 22126 - Don't print overlapped fields with -checkaction=context" fixing this issue: - Fix 22126 - Don't print overlapped fields with -checkaction=context Detect overlapped fields by checking the offsets of adjacent members. Those are replaced by a placeholder because we cannot determine wich of the overlapped fields is valid (if any). https://github.com/dlang/druntime/pull/3522

dlang/druntime pull request #3522 "Fix 22126 - Don't print overlapped fields with -checkaction=context" was merged into master: - 9b3989c827984e8f4f9acd253071d80ce24fe5e2 by MoonlightSentinel: Fix 22126 - Don't print overlapped fields with -checkaction=context Detect overlapped fields by checking the offsets of adjacent members. Those are replaced by a placeholder because we cannot determine wich of the overlapped fields is valid (if any). https://github.com/dlang/druntime/pull/3522