Fix compile on dist-i686-linux builder

If this lines are present then we apparently get errors [1] when compiling in
the current [2] dist-i686-linux container. Attempts to upgrade both gcc and
binutils did not fix the error, so it appears that this may just be a bug in the
super old glibc we're using on the dist-i686-linux container.

We don't actually need this code anyway, so just work around these issues by
removing references to the `*64` functions. This'll get things compiling
locally and shouldn't be a regression in functionality.

[1]: https://travis-ci.org/rust-lang/rust/jobs/257578199
[2]: https://github.com/rust-lang/rust/tree/eba9d7f08ce5c90549ee52337aca0010ad566f0d/src/ci/docker/dist-i686-linux

Author: alexcrichton

llvm/lib/ExecutionEngine/RuntimeDyld/RTDyldMemoryManager.cpp

@@ -243,9 +243,9 @@ RTDyldMemoryManager::getSymbolAddressInProcess(const std::string &Name) {
   if (Name == "stat") return (uint64_t)&stat;
   if (Name == "fstat") return (uint64_t)&fstat;
   if (Name == "lstat") return (uint64_t)&lstat;
-  if (Name == "stat64") return (uint64_t)&stat64;
-  if (Name == "fstat64") return (uint64_t)&fstat64;
-  if (Name == "lstat64") return (uint64_t)&lstat64;
+  // if (Name == "stat64") return (uint64_t)&stat64;
+  // if (Name == "fstat64") return (uint64_t)&fstat64;
+  // if (Name == "lstat64") return (uint64_t)&lstat64;
   if (Name == "atexit") return (uint64_t)&atexit;
   if (Name == "mknod") return (uint64_t)&mknod;