This adds MIDI support to the language as a new unstable feature. There
are two new metacommands that come with this:
$Unstable: Midi
$MidiSoundFont: [Default|"filename"]
The $Unstable command is required to be able to use any of the other
commands, and just signifies that this is not a full part of the
language yet and may change in breaking ways before the API is
finalized.
The $MidiSoundFont command enables MIDI support in the compiled program,
and also specifies what sound font to use to play MIDI files. "Default"
will make use of the soundfont placed at
'./internal/support/default_soundfont.sf2', and otherwise a filename can
be specified to use any soundfont wanted.
In either case, the selected sound font is compiled into the executable
and then loaded at runtime.
Fixes: #115
In QB64, when linking with an external static library `nm.exe` is used
to determine whether the symbol being used is either a C or C++ symbol,
which determines how the function should be declared in the C++ code.
Unfortunately on Windows the `SHELL` command for `nm.exe` is missing the
`cmd /c`, which means the redirection does not work and consequently
we're unable to find the function declaration via `nm.exe`, which causes
the compilation to fail.
In addition to fixing this, I added tests for `DECLARE STATIC LIBRARY`
for all supported platforms.
Fixes: #112
These tests check that we can compile programs that use a variety of
different sets of dependencies. Each program will only be compiled with
the set of dependencies it relies on.
