Test all register allocators in regalloc gtest

Previously, the gtest only exercised the default register allocator.
Note that the line count is high due mostly to whitespace changes.

Test: m test-art-host-gtest-register_allocator_test

Change-Id: I783edf98ae11d605d4f69834866c387abb71d34f
diff --git a/compiler/optimizing/locations.h b/compiler/optimizing/locations.h
index 2e94ad0..5fdfb9b 100644
--- a/compiler/optimizing/locations.h
+++ b/compiler/optimizing/locations.h
@@ -653,8 +653,7 @@
   // Whether these are locations for an intrinsified call.
   bool intrinsified_;
 
-  ART_FRIEND_TEST(RegisterAllocatorTest, ExpectedInRegisterHint);
-  ART_FRIEND_TEST(RegisterAllocatorTest, SameAsFirstInputHint);
+  friend class RegisterAllocatorTest;
   DISALLOW_COPY_AND_ASSIGN(LocationSummary);
 };