Revert "Make GCC happy again." and "Initial switch to Chromium-style CHECK_* and DCHECK_* macros.".

src/compiler/register-allocator-verifier.cc

Index: src/compiler/register-allocator-verifier.cc
diff --git a/src/compiler/register-allocator-verifier.cc b/src/compiler/register-allocator-verifier.cc
index 0f053331a6a998d3748deba3099b8544ce394ea4..d4471ff899c10b7c68e0e60af2f06f20957d3f68 100644
--- a/src/compiler/register-allocator-verifier.cc
+++ b/src/compiler/register-allocator-verifier.cc
@@ -20,7 +20,7 @@ static void VerifyGapEmpty(const GapInstruction* gap) {
        i <= GapInstruction::LAST_INNER_POSITION; i++) {
     GapInstruction::InnerPosition inner_pos =
         static_cast<GapInstruction::InnerPosition>(i);
-    CHECK(!gap->GetParallelMove(inner_pos));
+    CHECK_EQ(NULL, gap->GetParallelMove(inner_pos));
   }
 }
 
@@ -432,14 +432,14 @@ class OperandMap : public ZoneObject {
         for (; p != nullptr; p = p->first_pred_phi) {
           if (p->virtual_register == v->use_vreg) break;
         }
-        CHECK(p);
+        CHECK_NE(nullptr, p);
       }
       // Mark the use.
       it->second->use_vreg = use_vreg;
       return;
     }
     // Use of a phi value without definition.
-    UNREACHABLE();
+    CHECK(false);
   }
 
  private: