[turbofan] extend register allocator testing with control flow

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index ffbf2a3013dd3e4bcbf0c6808e78d0added9263f..e601b2c092f70209bf7014ebc66df435bf4a2f9b 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -66,11 +66,11 @@ void InstructionSelector::SelectInstructions() {
         sequence()->InstructionBlockAt(block->GetRpoNumber());
     size_t end = instruction_block->code_end();
     size_t start = instruction_block->code_start();
-    sequence()->StartBlock(block);
+    sequence()->StartBlock(block->GetRpoNumber());
     while (start-- > end) {
       sequence()->AddInstruction(instructions_[start]);
     }
-    sequence()->EndBlock(block);
+    sequence()->EndBlock(block->GetRpoNumber());
   }
 }