GNU library locations set incorrectly

[DavidHuber-NOAA]

Describe the bug
The gnu module file sets the library locations to $base/lib. However, there are no libraries located in this directory when built on S4 using the default settings. It may be that when built without 64-bit support, that libraries are located there, but with 64-bit support they are located in $base/lib64. The libgcc.a static library is located in $base/lib/gcc/x86_64-pc-linux-gnu/<version>, but all other static and dynamic libraries are located in $base/lib64.

To Reproduce
Build gnu/9.3.0 with 64-bit support.

Expected behavior
Libraries would be located where the module pointed to.

System:
S4

Additional context
N/A

[kgerheiser]

This is a recurring issue depending on the application. The GNU module needs some Lua logic to look for the library directory.