Emit the correct flags for the PROC CodeView Debug Symbol

The S_LPROC32_ID and S_GPROC32_ID CodeView Debug Symbols have a flags
field which LLVM has had the values for (in the ProcSymFlags enum) but
has never actually set.

These flags are used by Microsoft-internal tooling that leverages debug
information to do binary analysis.

Modified LLVM to set the correct flags:

- ProcSymFlags::HasOptimizedDebugInfo - always set, as this indicates that
debug info is present for optimized builds (if debug info is not emitted
for optimized builds, then LLVM won't emit a debug symbol at all).
- ProcSymFlags::IsNoReturn and ProcSymFlags::IsNoInline - set if the
function has the NoReturn or NoInline attributes respectively.
- ProcSymFlags::HasFP - set if the function requires a frame pointer (per
TargetFrameLowering::hasFP).

Differential Revision: https://reviews.llvm.org/D148761