[clang] NFC: Redundant code removal in SemaDecl.cpp, CheckTargetCausesMultiVersioning().

[tahonermann]

Summary

This change removes redundant code in the definition of
CheckTargetCausesMultiVersioning() in SemaDecl.cpp. The removed code checked
for multiversion function support. The code immediately following the removed
code is a call to CheckMultiVersionAdditionalRules(); that function performs
the same check on entry. In both cases, the consequences of missing multiversion
function support results in the same diagnostic message being issued and the
applicable function declaration being marked as invalid.

[tahonermann]

clang/lib/Sema/SemaDecl.cpp

10521–10526

This is the code that makes the removed code redundant.

[aaron.ballman]

LGTM!

clang/lib/Sema/SemaDecl.cpp

bool Sema::areMultiversionVariantFunctionsCompatible(
   }
   return false;
 }
 
 static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD,
                                              const FunctionDecl *NewFD,
                                              bool CausesMV,
                                              MultiVersionKind MVType) {
   if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
     S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
     if (OldFD)
       S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
     return true;
   }
 
   bool IsCPUSpecificCPUDispatchMVType =
       MVType == MultiVersionKind::CPUDispatch ||
       MVType == MultiVersionKind::CPUSpecific;
 
   if (CausesMV && OldFD &&
       checkNonMultiVersionCompatAttributes(S, OldFD, NewFD, MVType))
     return true;
static bool CheckTargetCausesMultiVersioning(
 
   // If the old decl is NOT MultiVersioned yet, and we don't cause that
   // to change, this is a simple redeclaration.
   if (!NewTA->isDefaultVersion() &&
       (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr()))
     return false;
 
   // Otherwise, this decl causes MultiVersioning.
-  if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
-    S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
-    S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
-    NewFD->setInvalidDecl();
-    return true;
-  }
-
   if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true,
                                        MultiVersionKind::Target)) {
     NewFD->setInvalidDecl();
     return true;
   }
 
   if (CheckMultiVersionValue(S, NewFD)) {
     NewFD->setInvalidDecl();