Fix perf degradation for method calls on polyglot arrays

This change stems from the investigation into elusive performance
degradation that became visible when implementing `Builder.to_vector`
with `slice` to not copy the store in
#3744.
We were seeing about 40% drop for a simple `filter` method calls
without any reason.

IGV debugging was fun, but didn't reveal much. Profiling with VisualVM
revealed that we were previously inlining most of nodes, while with the
new version that was no longer the case. Still, it was hard to figure
out why.

Decided to use
```
-Dpolyglot.engine.TraceDeoptimizeFrame=true
-Dpolyglot.engine.BackgroundCompilation=false
-Dpolyglot.engine.TraceCompilation=true
-Dpolyglot.engine.TraceInlining=true
```
which revealed a more than expected number of deoptimizations. With
```
-Dpolyglot.engine.TraceTransferToInterpreter=true
```
we were able to see the source of it:
```
[info] [2022-10-07T13:13:12.98Z] [engine] transferToInterpreter at
  Builder.to_vector<arg-2>(built-distribution/enso-engine-0.0.0-dev-linux-amd64/enso-0.0.0-dev/lib/Standard/Base/0.0.0-dev/src/Data/Vector.enso:1091) <split-c6d56df>
    Builder.to_vector(built-distribution/enso-engine-0.0.0-dev-linux-amd64/enso-0.0.0-dev/lib/Standard/Base/0.0.0-dev/src/Data/Vector.enso:1091) <split-6500912a>
    Vector.filter(built-distribution/enso-engine-0.0.0-dev-linux-amd64/enso-0.0.0-dev/lib/Standard/Base/0.0.0-dev/src/Data/Vector.enso:347) <split-660ff9b4>
    ...
    ...
  org.graalvm.truffle/com.oracle.truffle.api.CompilerDirectives.transferToInterpreterAndInvalidate(CompilerDirectives.java:90)
    org.enso.interpreter.node.callable.resolver.MethodResolverNodeGen.execute(MethodResolverNodeGen.java:47)
    org.enso.interpreter.node.callable.resolver.HostMethodCallNode.getPolyglotCallType(HostMethodCallNode.java:146)
    org.enso.interpreter.node.callable.InvokeMethodNodeGen.execute(InvokeMethodNodeGen.java:86)
    org.enso.interpreter.node.callable.InvokeCallableNode.invokeDynamicSymbol(InvokeCallableNode.java:254)
    org.enso.interpreter.node.callable.InvokeCallableNodeGen.execute(InvokeCallableNodeGen.java:54)
    org.enso.interpreter.node.callable.ApplicationNode.executeGeneric(ApplicationNode.java:99)
    org.enso.interpreter.node.ClosureRootNode.execute(ClosureRootNode.java:90)
```
So the problem was in the new implementation of `to_vector` but not in
`slice`, as we expected, but in `list.size`.

Problem was that `MethodResolver` would always deoptimize for polyglot
array method calls because newly created `UnresolvedSymbol` in
[HostMethodCallNode](https://github.com/enso-org/enso/blob/ea60cd5fab48d9f6b16923cea21620b97216a898/engine/runtime/src/main/java/org/enso/interpreter/node/callable/resolver/HostMethodCallNode.java#L145)
wouldn't `==` to the cached one in
[MethodResolver](https://github.com/enso-org/enso/blob/ea60cd5fab48d9f6b16923cea21620b97216a898/engine/runtime/src/main/java/org/enso/interpreter/node/callable/resolver/MethodResolverNode.java#L38).

Fixed by providing a custom `equals` implementation for
`UnresolvedSymbol` and `s/==/equals` in `MethodResolverNode` cache
check.

engine/runtime/src/main/java/org/enso/interpreter/node/callable/resolver/MethodResolverNode.java

@@ -35,7 +35,7 @@ public Function expectNonNull(Object self, Type type, UnresolvedSymbol symbol) {
   @Specialization(
       guards = {
         "!getContext().isInlineCachingDisabled()",
-        "cachedSymbol == symbol",
+        "cachedSymbol.equals(symbol)",
         "cachedType == type"
       },
       limit = "CACHE_SIZE")

engine/runtime/src/main/java/org/enso/interpreter/runtime/callable/UnresolvedSymbol.java

@@ -97,6 +97,15 @@ public boolean isExecutable() {
     return true;
   }
 
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) return true;
+    if (other instanceof UnresolvedSymbol sym) {
+      return this.name.equals(sym.getName()) && this.scope.equals(sym.getScope());
+    }
+    return false;
+  }
+
   /** Implements the logic of executing {@link UnresolvedSymbol} through the interop library. */
   @ExportMessage
   @ImportStatic(Constants.CacheSizes.class)