Remove the Android.mk GCC-only source files hackery

The complexity in Android.mk to deal with GCC-only source files is
unnecessary, use #if !defined(__clang__) around the contents of
interpreter/interpreter_goto_table_impl.cc, the same way
interpreter/interpreter.cc does around references to it.

Bug: 17716550
Change-Id: I775c23b6790d38b0d73a92529c696a31e6a4ae83
diff --git a/runtime/interpreter/interpreter_goto_table_impl.cc b/runtime/interpreter/interpreter_goto_table_impl.cc
index 5f97f94..af0a530 100644
--- a/runtime/interpreter/interpreter_goto_table_impl.cc
+++ b/runtime/interpreter/interpreter_goto_table_impl.cc
@@ -14,6 +14,9 @@
  * limitations under the License.
  */
 
+#if !defined(__clang__)
+// Clang 3.4 fails to build the goto interpreter implementation.
+
 #include "interpreter_common.h"
 #include "safe_math.h"
 
@@ -2477,3 +2480,5 @@
 
 }  // namespace interpreter
 }  // namespace art
+
+#endif