Embed Small and Optimized Debug Information for FPC

[DP News-Robot]

Debug information can be generated by compilers, to contain symbols and source code lines. This is very handy to have a meaningful stack trace on any problems like exceptions, at runtime.

The problem is that debug information can be huge. New code style with generics tends to increase this size into a bloated way...
On Delphi, mormot2tests generates a 4MB .map file;
on FPC, mormot2tests outputs a 20MB .dbg file in DWARF.