Mention that the LLVM/clang triple must be provided if the trace will be
consumed via `SBTraceCursor`
Test Plan:
Differential Revision: https://reviews.llvm.org/D137509
"pid": integer,
"triple"?: string,
// Optional clang/llvm target triple.
+ // This must be provided if the trace will be created not using the
+ // CLI or on a machine other than where the target was traced.
"threads": [
// A list of known threads for the given process. When context switch
// data is provided, LLDB will automatically create threads for the