Update hash.hpp to detect msvc

[abrady]

this causes errors when building on windows with cl:

[proc] Executing command: "C:\Program Files\CMake\bin\cmake.EXE" --build c:/open/Github/Vulk/build --config Debug --target PipelineBuilder -j 66 --
[build] MSBuild version 17.8.3+195e7f5a3 for .NET Framework
[build] 
[build]   Checking File Globs
[build]   Vulk.cpp
[build]   GLM_GTX_hash requires C++11 standard library support
[build]   VulkActor.cpp
[build]   GLM_GTX_hash requires C++11 standard library support
[build]   VulkCamera.cpp
[build]   GLM_GTX_hash requires C++11 standard library support
...

This change appears to fix it:

[proc] Executing command: "C:\Program Files\CMake\bin\cmake.EXE" --build c:/open/Github/Vulk/build --config Debug --target PipelineBuilder -j 66 --
[build] MSBuild version 17.8.3+195e7f5a3 for .NET Framework
[build] 
[build]   Checking File Globs
[build]   Vulk.cpp
[build]   VulkActor.cpp
[build]   VulkCamera.cpp

check out https://github.com/abrady/Vulk if you want to repro.

[christophe-lunarg]

This is resolved with #1274 thanks for contributing !