[IR] Remove deprecated opaque pointer migration methods

Remove the following methods:

 * Type::getNonOpaquePointerElementType()
 * Type::isOpaquePointerTy()
 * LLVMContext::supportsTypedPointers()
 * LLVMContext::setOpaquePointers()

These were used temporarily during the opaque pointers migration,
and are no longer needed.

Author: nikic

llvm/include/llvm/IR/LLVMContext.h

@@ -316,17 +316,6 @@ class LLVMContext {
   /// LLVMContext is used by compilation.
   void setOptPassGate(OptPassGate&);
 
-  /// Set whether opaque pointers are enabled. The method may be called multiple
-  /// times, but only with the same value. Note that creating a pointer type or
-  /// otherwise querying the opaque pointer mode performs an implicit set to
-  /// the default value.
-  [[deprecated("Opaque pointers are always enabled")]]
-  void setOpaquePointers(bool Enable) const;
-
-  /// Whether typed pointers are supported. If false, all pointers are opaque.
-  [[deprecated("Always returns false")]]
-  bool supportsTypedPointers() const;
-
   /// Get or set the current "default" target CPU (target-cpu function
   /// attribute). The intent is that compiler frontends will set this to a value
   /// that reflects the attribute that a function would get "by default" without

llvm/include/llvm/IR/Type.h

@@ -250,10 +250,6 @@ class Type {
   /// True if this is an instance of PointerType.
   bool isPointerTy() const { return getTypeID() == PointerTyID; }
 
-  /// True if this is an instance of an opaque PointerType.
-  LLVM_DEPRECATED("Use isPointerTy() instead", "isPointerTy")
-  bool isOpaquePointerTy() const { return isPointerTy(); };
-
   /// Return true if this is a pointer type or a vector of pointer types.
   bool isPtrOrPtrVectorTy() const { return getScalarType()->isPointerTy(); }
 
@@ -406,14 +402,6 @@ class Type {
 
   inline StringRef getTargetExtName() const;
 
-  /// Only use this method in code that is not reachable with opaque pointers,
-  /// or part of deprecated methods that will be removed as part of the opaque
-  /// pointers transition.
-  [[deprecated("Pointers no longer have element types")]]
-  Type *getNonOpaquePointerElementType() const {
-    llvm_unreachable("Pointers no longer have element types");
-  }
-
   /// Given vector type, change the element type,
   /// whilst keeping the old number of elements.
   /// For non-vectors simply returns \p EltTy.

llvm/lib/IR/LLVMContext.cpp

@@ -377,14 +377,6 @@ std::unique_ptr<DiagnosticHandler> LLVMContext::getDiagnosticHandler() {
   return std::move(pImpl->DiagHandler);
 }
 
-void LLVMContext::setOpaquePointers(bool Enable) const {
-  assert(Enable && "Cannot disable opaque pointers");
-}
-
-bool LLVMContext::supportsTypedPointers() const {
-  return false;
-}
-
 StringRef LLVMContext::getDefaultTargetCPU() {
   return pImpl->DefaultTargetCPU;
 }