[stubs] KeyedLoadIC_Megamorphic: use stub cache lookup as fallback

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index 9ae9da0f00628d673ee87cc505848cf7e71f2687..debf0c87a9067ccf6a5e201125e7dc751d279592 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -4869,7 +4869,7 @@ void CodeStubAssembler::KeyedLoadICGeneric(const LoadICParameters* p) {
     Variable var_name_index(this, MachineType::PointerRepresentation());
     Label if_descriptor_found(this);
     DescriptorLookupLinear(key, descriptors, nof, &if_descriptor_found,
-                           &var_name_index, &slow);
+                           &var_name_index, &stub_cache);
 
     Bind(&if_descriptor_found);
     {