[NFC] Silence Non-Exhaustive Switch Warnings on Windows

Author: CodaFi

include/swift/AST/Decl.h

@@ -3762,6 +3762,7 @@ struct SelfReferencePosition final {
     case Contravariant:
       return Covariant;
     }
+    llvm_unreachable("unhandled self reference position!");
   }
 
   explicit operator bool() const { return kind > None; }

include/swift/AST/ForeignErrorConvention.h

@@ -198,6 +198,7 @@ class ForeignErrorConvention {
     case NonNilError:
       return false;
     }
+    llvm_unreachable("unhandled foreign error kind!");
   }
 
   bool operator==(ForeignErrorConvention other) const {

include/swift/Demangling/TypeLookupError.h

@@ -150,6 +150,7 @@ class TypeLookupError {
         delete castContext;
         return nullptr;
       }
+      llvm_unreachable("unhandled command!");
     };
   }
 

include/swift/Sema/ConstraintSystem.h

@@ -1907,6 +1907,7 @@ class SolutionApplicationTarget {
     case Kind::patternBinding:
       return patternBinding;
     }
+    llvm_unreachable("invalid case label type");
   }
 
   VarDecl *getAsUninitializedWrappedVar() const {
@@ -1921,6 +1922,7 @@ class SolutionApplicationTarget {
     case Kind::uninitializedWrappedVar:
       return uninitializedWrappedVar;
     }
+    llvm_unreachable("invalid case label type");
   }
 
   BraceStmt *getFunctionBody() const {

lib/AST/AutoDiff.cpp

@@ -462,6 +462,7 @@ bool swift::operator==(const TangentPropertyInfo::Error &lhs,
   case TangentPropertyInfo::Error::Kind::TangentPropertyWrongType:
     return lhs.getType()->isEqual(rhs.getType());
   }
+  llvm_unreachable("unhandled tangent property!");
 }
 
 void swift::simple_display(llvm::raw_ostream &os, TangentPropertyInfo info) {

lib/AST/ClangTypeConverter.cpp

@@ -207,6 +207,7 @@ const clang::Type *ClangTypeConverter::getFunctionType(
   case SILFunctionType::Representation::Closure:
     llvm_unreachable("Expected a C-compatible representation.");
   }
+  llvm_unreachable("unhandled representation!");
 }
 
 clang::QualType ClangTypeConverter::convertMemberType(NominalTypeDecl *DC,

lib/AST/TypeCheckRequests.cpp

@@ -1497,6 +1497,7 @@ bool ActorIsolation::requiresSubstitution() const {
   case GlobalActor:
     return getGlobalActor()->hasTypeParameter();
   }
+  llvm_unreachable("unhandled actor isolation kind!");
 }
 
 ActorIsolation ActorIsolation::subst(SubstitutionMap subs) const {
@@ -1509,6 +1510,7 @@ ActorIsolation ActorIsolation::subst(SubstitutionMap subs) const {
   case GlobalActor:
     return forGlobalActor(getGlobalActor().subst(subs));
   }
+  llvm_unreachable("unhandled actor isolation kind!");
 }
 
 void swift::simple_display(

lib/Driver/DarwinToolChains.cpp

@@ -364,6 +364,7 @@ bool jobMatchesFilter(LinkKind jobKind, BackDeployLibFilter filter) {
   case BackDeployLibFilter::all:
     return true;
   }
+  llvm_unreachable("unhandled back deploy lib filter!");
 }
 
 }

lib/IDE/APIDigesterData.cpp

@@ -56,6 +56,7 @@ StringRef swift::ide::api::getDeclKindStr(const DeclKind Value, bool lower) {
     }
 #include "swift/AST/DeclNodes.def"
     }
+    llvm_unreachable("Unhandled DeclKind in switch.");
   } else {
     return getDeclKindStrRaw(Value);
   }

lib/IRGen/MetadataLayout.cpp

@@ -414,6 +414,7 @@ ClassMetadataLayout::getMethodInfo(IRGenFunction &IGF, SILDeclRef method) const{
   case MethodInfo::Kind::DirectImpl:
     return MethodInfo(stored.TheImpl);
   }
+  llvm_unreachable("unhandled method info kind!");
 }
 
 Offset ClassMetadataLayout::getFieldOffset(IRGenFunction &IGF,