Fix some warnings.

c++/src/capnproto/layout-test.c++

@@ -99,8 +99,6 @@ TEST(WireFormat, SimpleRawDataStruct) {
 }
 
 static const AlignedData<2> SUBSTRUCT_DEFAULT = {{0,0,0,0,1,0,0,0,  0,0,0,0,0,0,0,0}};
-static const AlignedData<3> STRUCTLIST_ELEMENT_DEFAULT =
-    {{0,0,0,0,1,0,1,0,  0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0}};
 static const AlignedData<2> STRUCTLIST_ELEMENT_SUBSTRUCT_DEFAULT =
     {{0,0,0,0,1,0,0,0,  0,0,0,0,0,0,0,0}};
 

c++/src/capnproto/serialize-packed.c++

@@ -178,6 +178,7 @@ size_t PackedInputStream::read(void* dst, size_t minBytes, size_t maxBytes) {
   }
 
   FAIL_CHECK("Can't get here.");
+  return 0;  // GCC knows FAIL_CHECK doesn't return, but Eclipse CDT still warns...
 
 #undef REFRESH_BUFFER
 }