[Exclusivity] Enable SILGen access marker emission by default.

This has no measurable effect on benchmarks and does not affect
standard library compile time.

Author: atrick

include/swift/AST/SILOptions.h

@@ -150,12 +150,6 @@ class SILOptions {
   /// Emit checks to trap at run time when the law of exclusivity is violated.
   bool EnforceExclusivityDynamic = false;
 
-  /// Returns true when either static or dynamic exclusivity enforcement
-  /// is enabled.
-  bool isAnyExclusivityEnforcementEnabled() {
-    return EnforceExclusivityStatic || EnforceExclusivityDynamic;
-  }
-
   /// Enable the mandatory semantic arc optimizer.
   bool EnableMandatorySemanticARCOpts = false;
 

lib/SIL/SILVerifier.cpp

@@ -1275,32 +1275,28 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     require(BAI->getType().isAddress(),
             "begin_access operand must have address type");
 
-    // Any kind of access marker can be used in the raw stage if either kind
-    // of enforcement is enabled globally.
+    // Any kind of access marker can be used in the raw stage.
     // After the raw stage, only dynamic access markers can be used, and
     // only if dynamic enforcement is enabled globally.
     // Eventually, we should allow access markers to persist in SIL, and
     // even make them obligatory, but we'll need to update a bunch of
     // passes first.
     switch (BAI->getEnforcement()) {
     case SILAccessEnforcement::Unknown:
-      require(F.getModule().getOptions().isAnyExclusivityEnforcementEnabled()
-              && BAI->getModule().getStage() == SILStage::Raw,
+      require(BAI->getModule().getStage() == SILStage::Raw,
               "access must have known enforcement outside raw stage");
       break;
 
     case SILAccessEnforcement::Static:
     case SILAccessEnforcement::Unsafe:
-      require(F.getModule().getOptions().isAnyExclusivityEnforcementEnabled()
-              && BAI->getModule().getStage() == SILStage::Raw,
+      require(BAI->getModule().getStage() == SILStage::Raw,
               "non-dynamic enforcement is currently disallowed outside "
               "raw stage");
       break;
 
     case SILAccessEnforcement::Dynamic:
-      require(F.getModule().getOptions().EnforceExclusivityDynamic ||
-              (F.getModule().getOptions().EnforceExclusivityStatic &&
-               BAI->getModule().getStage() == SILStage::Raw),
+      require(F.getModule().getOptions().EnforceExclusivityDynamic
+              || BAI->getModule().getStage() == SILStage::Raw,
               "dynamic access enforcement is only allowed after raw stage when "
               "globally enabled");
       break;

lib/SILGen/SILGenLValue.cpp

@@ -135,9 +135,7 @@ static bool shouldUseUnsafeEnforcement(VarDecl *var) {
 
 Optional<SILAccessEnforcement>
 SILGenFunction::getStaticEnforcement(VarDecl *var) {
-  if (getOptions().EnforceExclusivityStatic)
-    return SILAccessEnforcement::Static;
-  return None;
+  return SILAccessEnforcement::Static;
 }
 
 Optional<SILAccessEnforcement>
@@ -152,10 +150,7 @@ SILGenFunction::getDynamicEnforcement(VarDecl *var) {
 
 Optional<SILAccessEnforcement>
 SILGenFunction::getUnknownEnforcement(VarDecl *var) {
-  if (getOptions().EnforceExclusivityStatic ||
-      getOptions().EnforceExclusivityDynamic)
-    return SILAccessEnforcement::Unknown;
-  return None;
+  return SILAccessEnforcement::Unknown;
 }
 
 /// SILGenLValue - An ASTVisitor for building logical lvalues.

lib/SILOptimizer/Mandatory/AccessMarkerElimination.cpp

@@ -35,8 +35,6 @@ struct AccessMarkerElimination : SILModuleTransform {
     // Don't bother doing anything unless some kind of exclusivity
     // enforcement is enabled.
     auto &M = *getModule();
-    if (!M.getOptions().isAnyExclusivityEnforcementEnabled())
-      return;
 
     bool removedAny = false;