[lldb] Add nullptr check to SymbolVendorWasm

Add the same nullptr check to SymbolVendorWasm that was added to
SymbolVendorELF.

(cherry picked from commit e67460c)

Author: JDevlieghere

lldb/source/Plugins/SymbolVendor/wasm/SymbolVendorWasm.cpp

@@ -108,6 +108,9 @@ SymbolVendorWasm::CreateInstance(const lldb::ModuleSP &module_sp,
   SectionList *module_section_list = module_sp->GetSectionList();
   SectionList *objfile_section_list = sym_objfile_sp->GetSectionList();
 
+  if (!module_section_list || !objfile_section_list)
+    return nullptr;
+
   static const SectionType g_sections[] = {
       eSectionTypeDWARFDebugAbbrev,   eSectionTypeDWARFDebugAddr,
       eSectionTypeDWARFDebugAranges,  eSectionTypeDWARFDebugCuIndex,