Update DIL interpreter to return an error message for type casting.

Will replace this with code to do actual casts in next PR.

Author: cmtice

lldb/source/ValueObject/DILEval.cpp

@@ -748,8 +748,11 @@ Interpreter::Visit(const CastNode *node) {
 
   lldb::ValueObjectSP operand = *operand_or_err;
   // Don't actually do the cast for now -- that code will be added later.
-  // For now just return the original operand, unchanged.
-  return operand;
+  // For now just return an error message.
+  return llvm::make_error<DILDiagnosticError>(
+      m_expr,
+      "Type casting is not supported here.",
+      node->GetLocation());
 }
 
 } // namespace lldb_private::dil

lldb/source/ValueObject/DILParser.cpp

@@ -15,7 +15,6 @@
 #include "lldb/Symbol/CompileUnit.h"
 #include "lldb/Target/ExecutionContextScope.h"
 #include "lldb/Target/LanguageRuntime.h"
-#include "lldb/Utility/DiagnosticsRendering.h"
 #include "lldb/Host/common/DiagnosticsRendering.h"
 #include "lldb/Target/ExecutionContextScope.h"
 #include "lldb/ValueObject/DILAST.h"