Fix Clang-tidy readability-redundant-member-init warnings; other minor fixes
Fix Clang-tidy readability-redundant-member-init warnings; other minor fixes

Differential revision: https://reviews.llvm.org/D25931


git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@285086 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld