[NFC] Add some utilities in SILDeclRef

Author: meg-gupta

include/swift/SIL/SILDeclRef.h

@@ -306,6 +306,7 @@ struct SILDeclRef {
   AutoClosureExpr *getAutoClosureExpr() const;
   FuncDecl *getFuncDecl() const;
   AbstractFunctionDecl *getAbstractFunctionDecl() const;
+  AccessorDecl *getAccessorDecl() const;
   FileUnit *getFileUnit() const { return cast<FileUnit *>(loc); }
 
   /// Get ModuleDecl that contains the SILDeclRef
@@ -387,6 +388,10 @@ struct SILDeclRef {
 
   /// True if the SILDeclRef references an init accessor declaration.
   bool isInitAccessor() const;
+  /// True if the SILDeclRef references an borrow accessor declaration.
+  bool isBorrowAccessor() const;
+  /// True if the SILDeclRef references an mutate accessor declaration.
+  bool isMutateAccessor() const;
 
   /// True if the function should be treated as transparent.
   bool isTransparent() const;

lib/SIL/IR/SILDeclRef.cpp

@@ -804,16 +804,31 @@ AbstractFunctionDecl *SILDeclRef::getAbstractFunctionDecl() const {
   return dyn_cast_or_null<AbstractFunctionDecl>(getDecl());
 }
 
-bool SILDeclRef::isInitAccessor() const {
+AccessorDecl *SILDeclRef::getAccessorDecl() const {
   if (kind != Kind::Func || !hasDecl())
-    return false;
+    return nullptr;
+  return dyn_cast_or_null<AccessorDecl>(getDecl());
+}
 
-  if (auto accessor = dyn_cast<AccessorDecl>(getDecl()))
+bool SILDeclRef::isInitAccessor() const {
+  if (auto *accessor = getAccessorDecl())
     return accessor->getAccessorKind() == AccessorKind::Init;
 
   return false;
 }
 
+bool SILDeclRef::isMutateAccessor() const {
+  if (auto *accessor = getAccessorDecl())
+    return accessor->getAccessorKind() == AccessorKind::Mutate;
+  return false;
+}
+
+bool SILDeclRef::isBorrowAccessor() const {
+  if (auto *accessor = getAccessorDecl())
+    return accessor->getAccessorKind() == AccessorKind::Borrow;
+  return false;
+}
+
 /// True if the function should be treated as transparent.
 bool SILDeclRef::isTransparent() const {
   if (isEnumElement())