Reverting r275115 which caused PR28634.

When empty (forwarding) basic blocks that are referenced by user labels
are removed, incorrect code may be generated.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@276361 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGStmt.cpp

@@ -623,14 +623,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     RunCleanupsScope ThenScope(*this);
     EmitStmt(S.getThen());
   }
-  {
-    auto CurBlock = Builder.GetInsertBlock();
-    EmitBranch(ContBlock);
-    // Eliminate any empty blocks that may have been created by nested
-    // control flow statements in the 'then' clause.
-    if (CurBlock)
-      SimplifyForwardingBlocks(CurBlock); 
-  }
+  EmitBranch(ContBlock);
 
   // Emit the 'else' code if present.
   if (const Stmt *Else = S.getElse()) {
@@ -646,12 +639,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     {
       // There is no need to emit line number for an unconditional branch.
       auto NL = ApplyDebugLocation::CreateEmpty(*this);
-      auto CurBlock = Builder.GetInsertBlock();
       EmitBranch(ContBlock);
-      // Eliminate any empty blocks that may have been created by nested
-      // control flow statements emitted in the 'else' clause.
-      if (CurBlock)
-        SimplifyForwardingBlocks(CurBlock); 
     }
   }