[region-isolation] Add a print command that emits errors of the form "*-isolated code" or "code in the current task"

This makes it so that one does not need to deal with the differences in text in
between the task isolated case and the actor isolated case. This is done by
swallowing the entire part of this message in one method rather than having the
caller do the work.

Author: gottesmm

include/swift/SILOptimizer/Utils/SILIsolationInfo.h

@@ -291,6 +291,13 @@ class SILIsolationInfo {
     llvm::dbgs() << '\n';
   }
 
+  /// Prints out the message for a diagnostic that states that the value is
+  /// exposed to a specific code.
+  ///
+  /// We do this programatically since task-isolated code needs a very different
+  /// form of diagnostic than other cases.
+  void printForCodeDiagnostic(llvm::raw_ostream &os) const;
+
   void printForDiagnostics(llvm::raw_ostream &os) const;
 
   SWIFT_DEBUG_DUMPER(dumpForDiagnostics()) {
@@ -525,6 +532,10 @@ class SILDynamicMergedIsolationInfo {
     innerInfo.dumpForDiagnostics();
   }
 
+  void printForCodeDiagnostic(llvm::raw_ostream &os) const {
+    innerInfo.printForCodeDiagnostic(os);
+  }
+
   void printForOneLineLogging(llvm::raw_ostream &os) const {
     innerInfo.printForOneLineLogging(os);
   }

lib/SILOptimizer/Utils/SILIsolationInfo.cpp

@@ -1117,6 +1117,50 @@ void SILIsolationInfo::printForDiagnostics(llvm::raw_ostream &os) const {
   }
 }
 
+void SILIsolationInfo::printForCodeDiagnostic(llvm::raw_ostream &os) const {
+  switch (Kind(*this)) {
+  case Unknown:
+    llvm::report_fatal_error("Printing unknown for code diagnostic?!");
+    return;
+  case Disconnected:
+    llvm::report_fatal_error("Printing disconnected for code diagnostic?!");
+    return;
+  case Actor:
+    if (auto instance = getActorInstance()) {
+      switch (instance.getKind()) {
+      case ActorInstance::Kind::Value: {
+        SILValue value = instance.getValue();
+        if (auto name = VariableNameInferrer::inferName(value)) {
+          os << "'" << *name << "'-isolated code";
+          return;
+        }
+        break;
+      }
+      case ActorInstance::Kind::ActorAccessorInit:
+        os << "'self'-isolated code";
+        return;
+      case ActorInstance::Kind::CapturedActorSelf:
+        os << "'self'-isolated code";
+        return;
+      }
+    }
+
+    if (getActorIsolation().getKind() == ActorIsolation::ActorInstance) {
+      if (auto *vd = getActorIsolation().getActorInstance()) {
+        os << "'" << vd->getBaseIdentifier() << "'-isolated code";
+        return;
+      }
+    }
+
+    getActorIsolation().printForDiagnostics(os);
+    os << " code";
+    return;
+  case Task:
+    os << "code in the current task";
+    return;
+  }
+}
+
 void SILIsolationInfo::printForOneLineLogging(llvm::raw_ostream &os) const {
   switch (Kind(*this)) {
   case Unknown: