[turbofan] Introduce Float64Pow and NumberPow operators.

src/compiler/node-matchers.h

Index: src/compiler/node-matchers.h
diff --git a/src/compiler/node-matchers.h b/src/compiler/node-matchers.h
index 6238be30038aa80b9848f136274399767fd71984..93c091dc8a6869fa9c73f3892e16b0f6f9ac2d34 100644
--- a/src/compiler/node-matchers.h
+++ b/src/compiler/node-matchers.h
@@ -157,6 +157,7 @@ struct FloatMatcher final : public ValueMatcher<T, kOpcode> {
   bool IsMinusZero() const {
     return this->Is(0.0) && std::signbit(this->Value());
   }
+  bool IsNegative() const { return this->HasValue() && this->Value() < 0.0; }
   bool IsNaN() const { return this->HasValue() && std::isnan(this->Value()); }
   bool IsZero() const { return this->Is(0.0) && !std::signbit(this->Value()); }
 };