ART: Remove duplicate StackVisitor method.

Remove method that is the same as the older IsShadowFrame and only
used in tests.

Test: m ART_TEST_JIT=true ART_TEST_INTERPRETER=true test-art-host-run-test-454-get-vreg
Test: m ART_TEST_JIT=true ART_TEST_INTERPRETER=true test-art-host-run-test-457-regs
Test: m ART_TEST_JIT=true ART_TEST_INTERPRETER=true test-art-host-run-test-570-checker-osr
Change-Id: Id222d25d5345790b6c500ec8120880a3b9d79986
diff --git a/test/457-regs/regs_jni.cc b/test/457-regs/regs_jni.cc
index f62a77d..f867bdf 100644
--- a/test/457-regs/regs_jni.cc
+++ b/test/457-regs/regs_jni.cc
@@ -64,7 +64,7 @@
       CHECK_EQ(value, 1u);
 
       bool success = GetVReg(m, 2, kIntVReg, &value);
-      if (!IsCurrentFrameInInterpreter() && GetCurrentOatQuickMethodHeader()->IsOptimized()) {
+      if (!IsShadowFrame() && GetCurrentOatQuickMethodHeader()->IsOptimized()) {
         CHECK(!success);
       }