LLVM does not support aggregates larger than that at all, because internally
it stores all sizes in bits in an uint64. Their rationale for not having
special support for that is that there is no hardware with full 64 bit VM
address space anyway. So truncate our size emissions in debug info also to
that.
Fix MainSubprogram flag for older LLVM versions, as it was a plain flag rather
than a subprogram flag there.
Added visibility flags for procdefs (public/private/protected)
Write flags as enum rather than integer to avoid issues with changing values
across different LLVM versions
Ensures that breaking on the function correctly sets the breakpoint on the
first source line of the function (rather than potentially in the prologue
without line information)
LLVM requires line info metadata for all call instructions that may potentially
be inlined. So attach one to all call instructions in nolineinfo regions, but
set their line number to 0 (same as what clang does)
Does not make a difference for LLVM since all debug info for procdefs is
assigned to the definition instructions for the procdef anyway, and avoids
issues when only generating line info (in that case the structs will never
be processed, but we still have to generate the basic debug info for their
procdefs to provide a scope for their line info)
