[tests] Avoid deprecated except syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187928 91177308-0d34-0410-b5e6-96231b3b80d8
[tests] Make string encoding issues explicit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187929 91177308-0d34-0410-b5e6-96231b3b80d8
[lit] Make string encoding issues explicit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187931 91177308-0d34-0410-b5e6-96231b3b80d8
[lit] Explicitly convert dict items() result to a list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187932 91177308-0d34-0410-b5e6-96231b3b80d8