Add parens to force the order of operations in an expression trying to do "databuffer + offset" so that we don't overflow the uint64_t's  we're using for addresses when working with high addresses.
Add parens to force the order of operations in an expression trying
to do "databuffer + offset" so that we don't overflow the uint64_t's 
we're using for addresses when working with high addresses.

Found with clang's ubsan while doing darwin kernel debugging.

<rdar://problem/48728940> 



git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@355761 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb