[IR] Remove getDestAlignment and getSourceAlignment (llvm#151282)

This patch removes getDestAlignment and getSourceAlignment as they
have been deprecated for more than two years since:

  commit 135f23d
  Author: Guillaume Chatelet <[email protected]>
  Date:   Mon Jan 16 12:34:40 2023 +0000

I'm not aware of any downstream users AFAIK.

Author: kazutakahirata

llvm/include/llvm/IR/IntrinsicInst.h

@@ -996,14 +996,6 @@ template <typename Derived> class MemIntrinsicBase : public IntrinsicInst {
     return cast<PointerType>(getRawDest()->getType())->getAddressSpace();
   }
 
-  /// FIXME: Remove this function once transition to Align is over.
-  /// Use getDestAlign() instead.
-  LLVM_DEPRECATED("Use getDestAlign() instead", "getDestAlign")
-  unsigned getDestAlignment() const {
-    if (auto MA = getParamAlign(ARG_DEST))
-      return MA->value();
-    return 0;
-  }
   MaybeAlign getDestAlign() const { return getParamAlign(ARG_DEST); }
 
   /// Set the specified arguments of the instruction.
@@ -1057,15 +1049,6 @@ template <class BaseCL> class MemTransferBase : public BaseCL {
     return cast<PointerType>(getRawSource()->getType())->getAddressSpace();
   }
 
-  /// FIXME: Remove this function once transition to Align is over.
-  /// Use getSourceAlign() instead.
-  LLVM_DEPRECATED("Use getSourceAlign() instead", "getSourceAlign")
-  unsigned getSourceAlignment() const {
-    if (auto MA = BaseCL::getParamAlign(ARG_SOURCE))
-      return MA->value();
-    return 0;
-  }
-
   MaybeAlign getSourceAlign() const {
     return BaseCL::getParamAlign(ARG_SOURCE);
   }