oleaut32: TKIND_COCLASS parameters to Invoke'd functions should be converted into VT_DISPATCH instead of VT_UNKNOWN.

Add a test for this.

ole32: Fix BindCtxImpl_GetBindOptions to return the correct locale and to not fail if the input size is too large.

Also pass the right string to SymEnumSymbols and check for _ in symbol
name, instead of beginning of string.