[Transforms] Remove HasValueForBlock (NFC)

The function seems to be unused for at least one year.

Author: kazutakahirata

llvm/include/llvm/Transforms/Utils/SSAUpdaterBulk.h

@@ -70,10 +70,6 @@ class SSAUpdaterBulk {
   /// rewritten value when RewriteAllUses is called.
   void AddUse(unsigned Var, Use *U);
 
-  /// Return true if the SSAUpdater already has a value for the specified
-  /// variable in the specified block.
-  bool HasValueForBlock(unsigned Var, BasicBlock *BB);
-
   /// Perform all the necessary updates, including new PHI-nodes insertion and
   /// the requested uses update.
   ///

llvm/lib/Transforms/Utils/SSAUpdaterBulk.cpp

@@ -65,12 +65,6 @@ void SSAUpdaterBulk::AddUse(unsigned Var, Use *U) {
   Rewrites[Var].Uses.push_back(U);
 }
 
-/// Return true if the SSAUpdater already has a value for the specified variable
-/// in the specified block.
-bool SSAUpdaterBulk::HasValueForBlock(unsigned Var, BasicBlock *BB) {
-  return (Var < Rewrites.size()) ? Rewrites[Var].Defines.count(BB) : false;
-}
-
 // Compute value at the given block BB. We either should already know it, or we
 // should be able to recursively reach it going up dominator tree.
 Value *SSAUpdaterBulk::computeValueAt(BasicBlock *BB, RewriteInfo &R,