[vm] Add library private key to the Class hash function for reload.

This reduces isolate reload time on a given sample from ~2 seconds to ~200 milliseconds.
Remove ASSERT - you can have replacement finalized when original was non-finalized

Bug: #34461
Change-Id: I39dc5d67e97bd7c0d654cd751b6829b00337e967
Reviewed-on: https://dart-review.googlesource.com/74961
Commit-Queue: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>

Author: aam

runtime/vm/isolate_reload.cc

@@ -7,6 +7,9 @@
 #include "vm/bit_vector.h"
 #include "vm/compiler/jit/compiler.h"
 #include "vm/dart_api_impl.h"
+#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
+#include "vm/hash.h"
+#endif
 #include "vm/hash_table.h"
 #include "vm/heap/become.h"
 #include "vm/heap/safepoint.h"
@@ -328,7 +331,15 @@ class ClassMapTraits {
   }
 
   static uword Hash(const Object& obj) {
-    return String::HashRawSymbol(Class::Cast(obj).Name());
+    uword class_name_hash = String::HashRawSymbol(Class::Cast(obj).Name());
+    RawLibrary* raw_library = Class::Cast(obj).library();
+    if (raw_library == Library::null()) {
+      return class_name_hash;
+    }
+    return FinalizeHash(
+        CombineHashes(class_name_hash,
+                      String::Hash(Library::Handle(raw_library).private_key())),
+        /* hashbits= */ 30);
   }
 };
 

runtime/vm/object_reload.cc

@@ -591,7 +591,6 @@ void Class::CheckReload(const Class& replacement,
   if (is_prefinalized()) {
     if (!CanReloadPreFinalized(replacement, context)) return;
   }
-  ASSERT(is_finalized() == replacement.is_finalized());
   TIR_Print("Class `%s` can be reloaded (%" Pd " and %" Pd ")\n", ToCString(),
             id(), replacement.id());
 }