This test only applies when using the built-in LLVM version. This way,
we have a stable LLVM version to test against. Distribution versions of
LLVM (especially Debian) tend to be patched in a way that affect the
results.
This has two benefits:
1. It attributes these bytes to the internal/task package (in
-size=full), instead of (unknown).
2. It makes it possible to print the stack sizes variable in GDB.
This is what it might look like in GDB:
(gdb) p 'internal/task.stackSizes'
$13 = {344, 120, 80, 2048, 360, 112, 80, 120, 2048, 2048}
Previously we were using a really weird calculation to determine the
alignment in bits - written by me (no idea what I was thinking at the
time, it's obviously incorrect). Just replace it with the much more
obviously correct multiplication by 8 to get bits from bytes.
Found while working on properly dealing with alignment in `-size=full`.
The compiler now uses DW_OP_plus_uconst in the address attribute of
DWARF variables. To be able to understand these addresses, we need to be
able to parse this opcode.
This commit should also improve the reliability of address parsing a
bit.
Previously the code size of the compiler-rt library might be displayed
like this:
```
1050 0 0 0 | 1050 0 | /home/ayke/src/tinygo/tinygo/llvm-project/compiler-rt/lib/builtins
146 0 0 0 | 146 0 | /home/ayke/src/tinygo/tinygo/llvm-project/compiler-rt/lib/builtins/arm
```
With this change, it is displayed nicely like this:
```
1196 0 0 0 | 1196 0 | C compiler-rt
```
This should fix a number of concurrency/threading issues.
I had to force-disable concurrency in the linker using a hack. I'm not
entirely sure what the cause is, possibly the MinGW version (version 12
appears to work for me, while version 11 as used on the GitHub runner
image seems to be broken).
There are a few ways to fix this in a better way:
* Fix the underlying cause (possibly by upgrading to MinGW-w64 12).
* Add the `--threads` flag to the LLD MinGW linker, so we can use a
regular parameter instead of this hack.
