[Linux] Prefer higher versioned clang compilers to lower versions (#6824)

If the user does not specify which compiler to use via cache variables in
the CMake invocation, we perform a search for which version to use.
Previously this was done using a glob search on some pre-defined paths, and
then sorting the results using `list(SORT ... COMPARE NATURAL)`. Sorting in
this manner results in lower versions being moved to the head of the list.
The first result in the list was then used. Consequently, if the user has
`clang-11` and `clang-12` installed, `clang-11` was chosen.

This reverses the sort order so that the highest installed version is
chosen.

Signed-off-by: Chris Burel <burelc@amazon.com>

cmake/Platform/Linux/CompilerSettings_linux.cmake

@@ -19,7 +19,7 @@ if(NOT CMAKE_C_COMPILER AND NOT CMAKE_CXX_COMPILER AND NOT "$ENV{CC}" AND NOT "$
     file(GLOB clang_versions ${path_search})
     if(clang_versions)
         # Find and pick the highest installed version
-        list(SORT clang_versions COMPARE NATURAL)
+        list(SORT clang_versions COMPARE NATURAL ORDER DESCENDING)
         list(GET clang_versions 0 clang_higher_version_path)
         string(REGEX MATCH "clang-([0-9.]*)" clang_higher_version ${clang_higher_version_path})
         if(CMAKE_MATCH_1)