[turbofan] Fix incorrect minus zero handling in the unit tests.

testing/gmock-support.h

Index: testing/gmock-support.h
diff --git a/testing/gmock-support.h b/testing/gmock-support.h
index 44348b60e0e98bfe56c639f71f70fb1f5e114472..ad39e9269bb24404a7a9c52fd39f2479c2567f64 100644
--- a/testing/gmock-support.h
+++ b/testing/gmock-support.h
@@ -5,6 +5,8 @@
 #ifndef V8_TESTING_GMOCK_SUPPORT_H_
 #define V8_TESTING_GMOCK_SUPPORT_H_
 
+#include <cstring>
+
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace testing {
@@ -31,6 +33,25 @@ class Capture {
 
 namespace internal {
 
+struct AnyBitEq {
+  template <typename A, typename B>
+  bool operator()(A const& a, B const& b) const {
+    if (sizeof(A) != sizeof(B)) return false;
+    return std::memcmp(&a, &b, sizeof(A)) == 0;
+  }
+};
+
+
+template <typename Rhs>
+class BitEqMatcher : public ComparisonBase<BitEqMatcher<Rhs>, Rhs, AnyBitEq> {
+ public:
+  explicit BitEqMatcher(Rhs const& rhs)
+      : ComparisonBase<BitEqMatcher<Rhs>, Rhs, AnyBitEq>(rhs) {}
+  static const char* Desc() { return "is bitwise equal to"; }
+  static const char* NegatedDesc() { return "isn't bitwise equal to"; }
+};
+
+
 template <typename T>
 class CaptureEqMatcher : public MatcherInterface<T> {
  public:
@@ -60,10 +81,18 @@ class CaptureEqMatcher : public MatcherInterface<T> {
 }  // namespace internal
 
 
+// Creates a polymorphic matcher that matches anything whose bit representation
+// is equal to that of x.
+template <typename T>
+inline internal::BitEqMatcher<T> BitEq(T const& x) {
+  return internal::BitEqMatcher<T>(x);
+}
+
+
 // CaptureEq(capture) captures the value passed in during matching as long as it
 // is unset, and once set, compares the value for equality with the argument.
 template <typename T>
-Matcher<T> CaptureEq(Capture<T>* capture) {
+inline Matcher<T> CaptureEq(Capture<T>* capture) {
   return MakeMatcher(new internal::CaptureEqMatcher<T>(capture));
 }