tests: [diag] resolve add-on against host only (drop orc_rt PlatformJD from link order)

Author: jcelerier

tests/jit-min/main.cpp

@@ -153,24 +153,14 @@ int main(int argc, char** argv)
     errs().flush();
   }
 
-  // FIX TEST: orc_rt.a statically links a partial libc++abi, so the add-on
-  // resolves the cxxabi RTTI vtables + __dynamic_cast to orc_rt's copies in the
-  // slab instead of the host libc++.dll. orc_rt's __vmi vtable is incomplete ->
-  // multiple-inheritance dynamic_cast crashes. Pin these to the host copies.
-  {
-    auto& ES = (*jit)->getExecutionSession();
-    SymbolMap host;
-    for(const char* sym :
-        {"_ZTVN10__cxxabiv117__class_type_infoE",
-         "_ZTVN10__cxxabiv120__si_class_type_infoE",
-         "_ZTVN10__cxxabiv121__vmi_class_type_infoE", "__dynamic_cast"})
-    {
-      if(void* a = sys::DynamicLibrary::SearchForAddressOfSymbol(sym))
-        host[ES.intern(sym)] = {ExecutorAddr::fromPtr(a), JITSymbolFlags::Exported};
-    }
-    if(auto E = JD.define(absoluteSymbols(std::move(host))))
-      fail("pin cxxabi to host", std::move(E));
-  }
+  // FIX TEST: keep orc_rt's PlatformJD (which statically embeds a partial
+  // libc++abi -- incomplete __vmi RTTI) out of the ADD-ON's link order. The
+  // add-on's own code only needs the host libc++ + its own symbols; the platform
+  // uses orc_rt internally (section registration / init), not via the add-on's
+  // symbol resolution. So resolve the add-on against the host process only.
+  JD.setLinkOrder(
+      makeJITDylibSearchOrder(&JD, JITDylibLookupFlags::MatchAllSymbols),
+      /*LinkAgainstThisJITDylibFirst=*/false);
 
   // x86_64-w64-windows-gnu always lowers thread_local through emulated TLS
   // (__emutls_get_address); compiler-rt provides it but the host exe doesn't