Improved exception stack frame displayed data.

Sequence points are now always generated and and we can use them to retrieve IL offsets from native offsets.

Stack traces now show native base offset.

Stack traces now also display the IL offset in Release mode, that can be used later on to obtain a code line from the .mdb file.

A stack trace of a Release .exe now looks like:
```
System.Exception:
  at Program.Test () [IL 0x0000c] in 0x1067d2930 + 0x0009f 
  at Program.Main () [IL 0x0000a] in 0x106714110 + 0x0007b 
```

Improved how sequence points are stored in memory. 
 The sequence point encoding is now 2+ bytes or 5+ bytes when the Debugger agent is used. (It was 20+ bytes)

Here is the allocated code size  and sequence points size for HelloWorld.
```
Allocated code size                 : 88253
Allocated seq points size           : 4381 (Release)
Allocated seq points size           : 12032 (Debug)
```
The  sequence points size represents **5%**(Release) and **14%**(Debug) of the code size.
Needs to be updated.