Tidy logging code not using UNIMPLEMENTED.

Change-Id: I7a79c1671a6ff8b2040887133b3e0925ef9a3cfe
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index 9fb9a3b..ccc5d83 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -499,11 +499,8 @@
     case StaticPrimitiveRead:    is_primitive = true;  is_set = false; is_static = true;  break;
     case StaticPrimitiveWrite:   is_primitive = true;  is_set = true;  is_static = true;  break;
     default:
-      LOG(FATAL) << "UNREACHABLE";  // Assignment below to avoid GCC warnings.
-      is_primitive = true;
-      is_set = true;
-      is_static = true;
-      break;
+      LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
   if (UNLIKELY(resolved_field->IsStatic() != is_static)) {
     // Incompatible class change.
diff --git a/runtime/entrypoints/portable/portable_trampoline_entrypoints.cc b/runtime/entrypoints/portable/portable_trampoline_entrypoints.cc
index c3664bf..61d66ba 100644
--- a/runtime/entrypoints/portable/portable_trampoline_entrypoints.cc
+++ b/runtime/entrypoints/portable/portable_trampoline_entrypoints.cc
@@ -172,7 +172,7 @@
         break;
       case Primitive::kPrimVoid:
         LOG(FATAL) << "UNREACHABLE";
-        break;
+        UNREACHABLE();
     }
     ++cur_reg_;
   }
@@ -261,8 +261,7 @@
         break;
       case Primitive::kPrimVoid:
         LOG(FATAL) << "UNREACHABLE";
-        val.j = 0;
-        break;
+        UNREACHABLE();
     }
     args_.push_back(val);
   }
diff --git a/runtime/entrypoints/quick/quick_alloc_entrypoints.cc b/runtime/entrypoints/quick/quick_alloc_entrypoints.cc
index a2869ec..7dbfdd5 100644
--- a/runtime/entrypoints/quick/quick_alloc_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_alloc_entrypoints.cc
@@ -248,7 +248,8 @@
     }
 #endif
     default: {
-      LOG(FATAL) << "Unimplemented";
+      UNIMPLEMENTED(FATAL);
+      UNREACHABLE();
     }
   }
 }
diff --git a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
index af341bb..2e38c3a 100644
--- a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
@@ -456,7 +456,7 @@
       break;
     case Primitive::kPrimVoid:
       LOG(FATAL) << "UNREACHABLE";
-      break;
+      UNREACHABLE();
   }
   ++cur_reg_;
 }
@@ -564,8 +564,7 @@
       break;
     case Primitive::kPrimVoid:
       LOG(FATAL) << "UNREACHABLE";
-      val.j = 0;
-      break;
+      UNREACHABLE();
   }
   args_->push_back(val);
 }
@@ -1557,7 +1556,7 @@
       break;
     case Primitive::kPrimVoid:
       LOG(FATAL) << "UNREACHABLE";
-      break;
+      UNREACHABLE();
   }
 }