Make feupdateenv() in H5Tinit_float.c Optional

**Is your feature request related to a problem? Please describe.**

An application that calls H5Pcreate(H5P_FILE_CREATE) hangs when it is built with gcc/g++-5.2.0 on CentOS5 x86_64.

Compiler warning:

```
libhdf5.a(H5Tinit_float.o): In function `H5T_inint_native_float_tpes':
H5Tinint_float.c:(.text+0x29): warning: warning: feupdateenv is not implemented and will always fail
```
**Describe the solution you'd like**

Make the feupdateenv() call optional via configuration or disable it automatically when configure detects old compiler.

**Describe alternatives you've considered**

Commenting out the line worked fine for [the legacy C++ app](https://github.com/hyoklee/hpf/blob/1.0.0/src/examples/cpp/many_dsets.cpp).

**Additional context**

I don't see the same issue on CentOS5 i386. I don't know why.