Bazel & TensorFlow easyblocks expect to find include-fixed subdirectory in GCC installation

```
$ eb Bazel-2.0.0-GCCcore-8.3.0.eb
...
== FAILED: Installation ended unsuccessfully (build directory: /tmp/Bazel/2.0.0/GCCcore-8.3.0):
build failed (first 300 chars): Derived directory /software/GCCcore/8.3.0/lib/gcc/x86_64-pc-linux-gnu/8.3.0/include-fixed does not exist (took 9 sec)
```

This issue is caused by the changes in #2087.