Fix 2 new sets of clang compiler warnings.

Fix issues that are flagged by -Wfloat-equal and -Wmissing-noreturn.
In the case of -Wfloat-equal the current cases in regular code are deliberate,
so the change is to silence the warning. For gtest code the appropriate fix is
to switch from EXPECT_EQ to EXPECT_(FLOAT|DOUBLE)_EQ.
The -Wmissing-noreturn warning isn't enabled due to a missing noreturn in
gtest. This issue has been reported to gtest.

Change-Id: Id84c70c21c542716c9ee0c41492e8ff8788c4ef8
diff --git a/runtime/interpreter/interpreter_switch_impl.cc b/runtime/interpreter/interpreter_switch_impl.cc
index fe0af27..14e8a52 100644
--- a/runtime/interpreter/interpreter_switch_impl.cc
+++ b/runtime/interpreter/interpreter_switch_impl.cc
@@ -562,6 +562,12 @@
         inst = inst->RelativeAt(offset);
         break;
       }
+
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wfloat-equal"
+#endif
+
       case Instruction::CMPL_FLOAT: {
         PREAMBLE();
         float val1 = shadow_frame.GetVRegFloat(inst->VRegB_23x());
@@ -627,6 +633,11 @@
         inst = inst->Next_2xx();
         break;
       }
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
       case Instruction::CMP_LONG: {
         PREAMBLE();
         int64_t val1 = shadow_frame.GetVRegLong(inst->VRegB_23x());