[turbofan] Introduce TruncateTaggedToWord32 simplified operator.

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index f71378c503a7f8e6dd093e7454c5ea79b3e5c72b..baad9838703f33ad3e1f546c01a25041094657c5 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -169,8 +169,6 @@ class CodeStubAssembler : public compiler::CodeAssembler {
                                           compiler::Node* value);
   compiler::Node* TruncateTaggedToWord32(compiler::Node* context,
                                          compiler::Node* value);
-  // Truncate to int32 using JavaScript truncation mode.
-  compiler::Node* TruncateFloat64ToInt32(compiler::Node* value);
   // Truncate the floating point value of a HeapNumber to an Int32.
   compiler::Node* TruncateHeapNumberValueToWord32(compiler::Node* object);