Fix a couple .NET 9 testing issues in the SOS tests in the diagnostics repo (#99255)

* Fix SOS DAC GetAssemblyData failure from ClassLoader not being in core dump

* Bump the MacOS stack overflow stack size

Author: Mike McLaughlin

src/coreclr/debug/daccess/request.cpp

@@ -2577,7 +2577,7 @@ ClrDataAccess::GetAssemblyData(CLRDATA_ADDRESS cdBaseDomainPtr, CLRDATA_ADDRESS
     }
 
     assemblyData->AssemblyPtr = HOST_CDADDR(pAssembly);
-    assemblyData->ClassLoader = HOST_CDADDR(pAssembly->GetLoader());
+    assemblyData->ClassLoader = 0;
     assemblyData->ParentDomain = HOST_CDADDR(AppDomain::GetCurrentDomain());
     assemblyData->isDynamic = pAssembly->IsDynamic();
     assemblyData->ModuleCount = 0;

src/coreclr/pal/src/exception/machexception.cpp

@@ -849,7 +849,7 @@ HijackFaultingThread(
     if (fIsStackOverflow)
     {
         // Allocate the minimal stack necessary for handling stack overflow
-        int stackOverflowStackSize = 7 * 4096;
+        int stackOverflowStackSize = 15 * 4096;
         // Align the size to virtual page size and add one virtual page as a stack guard
         stackOverflowStackSize = ALIGN_UP(stackOverflowStackSize, GetVirtualPageSize()) + GetVirtualPageSize();
         void* stackOverflowHandlerStack = mmap(NULL, stackOverflowStackSize, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);