[llc] Remove exit-on-error flag (PR27759)

[rovka]

Summary

This flag was introduced in r269655 with the new diagnostic handler for llc. Its purpose was to keep the old behavior for some of the tests that didn't recover well after an error. Those tests have been fixed, so now it's safe to remove the flag entirely.

Fixes PR27759.

! NOTE ! The AMDGPU tests are still pending (D20852).

[rnk]

lgtm

tools/llc/llc.cpp

CompileTwice("compile-twice", cl::Hidden,
                           "manager and verify the result is the same."),
                  cl::init(false));
 
 static cl::opt<bool> DiscardValueNames(
     "discard-value-names",
     cl::desc("Discard names from Value (other than GlobalValue)."),
     cl::init(false), cl::Hidden);
 
-static cl::opt<bool> ExitOnError(
-    "exit-on-error",
-    cl::desc("Exit as soon as an error is encountered."),
-    cl::init(false), cl::Hidden);
-
 namespace {
 static ManagedStatic<std::vector<std::string>> RunPassNames;
 
 struct RunPassOption {
   void operator=(const std::string &Val) const {
     if (Val.empty())
       return;
     SmallVector<StringRef, 8> PassNames;
int main(int argc, char **argv) {
   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
 
   cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
 
   Context.setDiscardValueNames(DiscardValueNames);
 
   // Set a diagnostic handler that doesn't exit on the first error
   bool HasError = false;
-  if (!ExitOnError)
-    Context.setDiagnosticHandler(DiagnosticHandler, &HasError);
 
   // Compile the module TimeCompilations times to give better compile time
   // metrics.
   for (unsigned I = TimeCompilations; I; --I)
     if (int RetVal = compileModule(argv, Context))
       return RetVal;
   return 0;
 }
if (CompileTwice) {
       std::unique_ptr<Module> M2(llvm::CloneModule(M.get()));
       PM.run(*M2);
       CompileTwiceBuffer = Buffer;
       Buffer.clear();
     }
 
     PM.run(*M);
 
-    if (!ExitOnError) {
-      auto HasError = *static_cast<bool *>(Context.getDiagnosticContext());
-      if (HasError)
-        return 1;
-    }
 
     // Compare the two outputs and make sure they're the same
     if (CompileTwice) {
       if (Buffer.size() != CompileTwiceBuffer.size() ||
           (memcmp(Buffer.data(), CompileTwiceBuffer.data(), Buffer.size()) !=
            0)) {
         errs()
             << "Running the pass manager twice changed the output.\n"