Handle minimal MethodTables in dotnet-pgo trace processing (#127818)

BulkType ETW events emit `TypeNameID = th.GetCl()`
(eventtrace_bulktype.cpp). For "minimal" MethodTables created by
`CreateMinimalMethodTable` (used for Reflection.Emit DynamicMethod hosts
in dynamicmethod.cpp and the IL stub cache in ilstubcache.cpp), `SetCl`
is never called, so `GetCl` returns `mdTypeDefNil` (0x02000000, rid 0).

dotnet-pgo previously treated this as a valid TypeDef token, and the
lazy `EcmaType.Name` access would throw `BadImageFormatException: Read
out of bounds` because rid 0 is before the typedef table.

Validate the typedef row before constructing the `TypeDefinitionHandle`
and treat out-of-range rids (rid 0, or rid greater than the typedef
table size) as unresolvable dynamic types so trace processing can
continue.

This started failing on the SDK training pipeline after #126330 (Migrate
CLR to COM stubs to be IL stubs) and #125352 (Move struct marshaling to
transient IL) flowed through, which routed new categories of stubs
through the minimal-MT path and added their BulkType events to the
trace.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: DrewScoggins

src/coreclr/tools/dotnet-pgo/TraceRuntimeDescToTypeSystemDesc.cs

@@ -405,7 +405,18 @@ public TypeDesc ResolveTypeHandle(long handle, ref bool dependsOnKnownNonLoadabl
                             throw new Exception($"Invalid typedef {tinfo.TypeValue.TypeNameID:4x}");
                         }
 
-                        TypeDefinitionHandle typedef = MetadataTokens.TypeDefinitionHandle(tinfo.TypeValue.TypeNameID & 0xFFFFFF);
+                        int typedefRow = tinfo.TypeValue.TypeNameID & 0xFFFFFF;
+                        // The runtime emits BulkType events for "minimal" MethodTables created by
+                        // CreateMinimalMethodTable in coreclr (used for Reflection.Emit DynamicMethod
+                        // hosts and the IL stub cache). These MTs have no typedef token and surface
+                        // here as TypeNameID == 0x02000000 (rid 0). Treat them as unresolvable
+                        // dynamic types so trace processing can continue.
+                        if (typedefRow == 0)
+                        {
+                            dependsOnKnownNonLoadableType = true;
+                            return null;
+                        }
+                        TypeDefinitionHandle typedef = MetadataTokens.TypeDefinitionHandle(typedefRow);
                         MetadataType uninstantiatedType = (MetadataType)ecmaModule.GetType(typedef);
                         // Instantiate the type if requested
                         if ((tinfo.TypeValue.TypeParameters.Length != 0) && uninstantiatedType != null)