[mlir] Elide large elements attrs when printing Operations in diagnostics

[rriddle]

Summary

Diagnostics are intended to be read by users, and in most cases displayed in a terminal. When not eliding huge element attributes, in some cases we end up dumping hundreds of megabytes(gigabytes) to the terminal (or logs), completely obfuscating the main diagnostic being shown.

mlir/lib/IR/Diagnostics.cpp

Diagnostic &Diagnostic::operator<<(OperationName val) {
   arguments.push_back(DiagnosticArgument(val.getStringRef()));
   return *this;
 }
 
 /// Stream in an Operation.
 Diagnostic &Diagnostic::operator<<(Operation &val) {
   std::string str;
   llvm::raw_string_ostream os(str);
-  os << val;
+  val.print(os, OpPrintingFlags().useLocalScope().elideLargeElementsAttrs());
   return *this << os.str();
 }
 
 /// Outputs this diagnostic to a stream.
 void Diagnostic::print(raw_ostream &os) const {
   for (auto &arg : getArguments())
     arg.print(os);
 }