Enable enforce-exclusivity=checked at -Onone.

This enables dynamic checking at -Onone.

Static checking is enabled by default regardless of optimizations.

SILGen only emits dynamic markers at -Onone, or when explicitly requested with
-enforce-exclusivity=checked|dynamic.

All access markers are stripped at the start of the optimization pipeline
regardless of optimization level or command line flags.

lib/Frontend/CompilerInvocation.cpp

@@ -1414,6 +1414,8 @@ static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
     IRGenOpts.Sanitize = Opts.Sanitize;
   }
 
+  if (Opts.Optimization > SILOptions::SILOptMode::None)
+    Opts.EnforceExclusivityDynamic = false;
   if (const Arg *A = Args.getLastArg(options::OPT_enforce_exclusivity_EQ)) {
     parseExclusivityEnforcementOptions(A, Opts, Diags);
   }