Replace magic number with sizeof(). No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194877 91177308-0d34-0410-b5e6-96231b3b80d8
Duplicate code removal.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194887 91177308-0d34-0410-b5e6-96231b3b80d8
Use llvm_unreachable() instead of assert() at where control should never get.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194890 91177308-0d34-0410-b5e6-96231b3b80d8
Use range-based for loop.

end() was evaluated every time through a loop. This patch eliminates it.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@194894 91177308-0d34-0410-b5e6-96231b3b80d8