[region-isolation] Some small gardening updates in preparation for the next commit.

Specifically, I added a few helper methods and improved the logging printing.
This all makes the next commit a more focused commit.

(cherry picked from commit 9bfb3b7)

Author: gottesmm

include/swift/AST/ActorIsolation.h

@@ -205,6 +205,8 @@ class ActorIsolation {
     return getKind() == GlobalActor;
   }
 
+  bool isActorInstanceIsolated() const { return getKind() == ActorInstance; }
+
   bool isMainActor() const;
 
   bool isDistributedActor() const;
@@ -262,29 +264,7 @@ class ActorIsolation {
                               state.parameterIndex);
   }
 
-  void print(llvm::raw_ostream &os) const {
-    switch (getKind()) {
-    case Unspecified:
-      os << "unspecified";
-      return;
-    case ActorInstance:
-      os << "actor_instance";
-      return;
-    case Nonisolated:
-      os << "nonisolated";
-      return;
-    case NonisolatedUnsafe:
-      os << "nonisolated_unsafe";
-      return;
-    case GlobalActor:
-      os << "global_actor";
-      return;
-    case Erased:
-      os << "erased";
-      return;
-    }
-    llvm_unreachable("Covered switch isn't covered?!");
-  }
+  void print(llvm::raw_ostream &os) const;
 
   void printForDiagnostics(llvm::raw_ostream &os,
                            StringRef openingQuotationMark = "'") const;

include/swift/SIL/SILFunction.h

@@ -1539,6 +1539,17 @@ class SILFunction
     return getArguments().back();
   }
 
+  /// If we have an isolated argument, return that. Returns nullptr otherwise.
+  const SILArgument *maybeGetIsolatedArgument() const {
+    for (auto *arg : getArgumentsWithoutIndirectResults()) {
+      if (cast<SILFunctionArgument>(arg)->getKnownParameterInfo().hasOption(
+              SILParameterInfo::Isolated))
+        return arg;
+    }
+
+    return nullptr;
+  }
+
   const SILArgument *getDynamicSelfMetadata() const {
     assert(hasDynamicSelfMetadata() && "This method can only be called if the "
            "SILFunction has a self-metadata parameter");

include/swift/SILOptimizer/Analysis/RegionAnalysis.h

@@ -305,7 +305,10 @@ class regionanalysisimpl::TrackableValue {
     os << "\n    Rep Value: " << getRepresentative();
   }
 
-  SWIFT_DEBUG_DUMP { print(llvm::dbgs()); }
+  SWIFT_DEBUG_DUMP {
+    print(llvm::dbgs());
+    llvm::dbgs() << '\n';
+  }
 };
 
 class RegionAnalysis;

lib/AST/TypeCheckRequests.cpp

@@ -1733,6 +1733,33 @@ void ActorIsolation::printForDiagnostics(llvm::raw_ostream &os,
   }
 }
 
+void ActorIsolation::print(llvm::raw_ostream &os) const {
+  switch (getKind()) {
+  case Unspecified:
+    os << "unspecified";
+    return;
+  case ActorInstance:
+    os << "actor_instance";
+    if (auto *vd = getActorInstance()) {
+      os << ". name: '" << vd->getBaseIdentifier() << "'";
+    }
+    return;
+  case Nonisolated:
+    os << "nonisolated";
+    return;
+  case NonisolatedUnsafe:
+    os << "nonisolated_unsafe";
+    return;
+  case GlobalActor:
+    os << "global_actor. type: " << getGlobalActor();
+    return;
+  case Erased:
+    os << "erased";
+    return;
+  }
+  llvm_unreachable("Covered switch isn't covered?!");
+}
+
 void ActorIsolation::dumpForDiagnostics() const {
   printForDiagnostics(llvm::dbgs());
   llvm::dbgs() << '\n';

lib/SIL/IR/SILPrinter.cpp

@@ -3314,6 +3314,12 @@ void SILFunction::print(SILPrintContext &PrintCtx) const {
     P.printDebugScopeRef(getDebugScope(), SM);
   }
   OS << '\n';
+
+  if (auto functionIsolation = getActorIsolation()) {
+    OS << "// Isolation: ";
+    functionIsolation.print(OS);
+    OS << '\n';
+  }
   printClangQualifiedNameCommentIfPresent(OS, getClangDecl());
 
   OS << "sil ";

lib/SILOptimizer/Utils/PartitionUtils.cpp

@@ -398,10 +398,26 @@ void SILIsolationInfo::print(llvm::raw_ostream &os) const {
     os << "disconnected";
     return;
   case Actor:
-    os << "actor";
+    if (SILValue instance = getActorInstance()) {
+      if (auto name = VariableNameInferrer::inferName(instance)) {
+        os << "'" << *name << "'-isolated\n";
+        os << "instance: " << *instance;
+        return;
+      }
+    }
+
+    if (getActorIsolation().getKind() == ActorIsolation::ActorInstance) {
+      if (auto *vd = getActorIsolation().getActorInstance()) {
+        os << "'" << vd->getBaseIdentifier() << "'-isolated";
+        return;
+      }
+    }
+
+    getActorIsolation().printForDiagnostics(os);
     return;
   case Task:
-    os << "task";
+    os << "task-isolated\n";
+    os << "instance: " << *getIsolatedValue();
     return;
   }
 }