A class declared in a unit's implementation section (IsImplPrivate) referenced
as a metaclass value in that same unit's initialization block — e.g.
RegisterTest(TFoo) — could be emitted under a bare, unqualified, undefined
typeinfo symbol, linking to garbage and crashing at runtime.
Per-unit codegen sets the symbol-table viewing context (DefineOwningUnit) to the
unit being emitted, so TSymbolTable.Lookup's cross-unit-leak guard does not
suppress the unit's own impl-section types. But earlier emit passes in EmitUnit
(method-body type resolution that walks the uses chain) leave DefineOwningUnit
pointing at a dependency unit. By the time the class-data section and the
initialization block are emitted, a metaclass reference to an impl-section class
resolved to nil and ClassSymName/ClassUnitPrefix fell back to the bare class
name. Only per-unit separate compilation exposed this; whole-program emit-ir
mode kept the context stable, so all fixpoints and the IR harness passed while
the linked binary held a garbage typeinfo pointer.
Re-assert DefineOwningUnit := AUnit.Name immediately before the class-data
section emission and before the initialization-block emission, in both the
native x86-64 and QBE backends.
Add Test{Native,QBE}ImplSectionMetaclassInInit_Runs to cp.test.e2e.sepcompile,
exercising an impl-section class assigned to a class-of global in the unit's own
init on both backends.
7979f23eb1