The sizeof() operator returns the size of an object or type in bytes,
not bits. Instead of calculating the number of bits using, e.g.,
CHAR_BIT * sizeof(), hard-code 64 since it is close to the declaration.

This is a prerequisite for HBM support with up to 32 channels.

Link: #3137
Fixes: 7bf96dc ("mem_tg test multichannel")
Signed-off-by: Peter Colberg <[email protected]>

Replace manual memory allocation using new[] and delete[] with
std::vector, which avoids unintended memory leaks. Drop unneeded
vectors for per-thread promise and tg_exe, which may be stored
as local variables inside the lambda function. The lambda is
declared as mutable to permit moving the promise.

Signed-off-by: Peter Colberg <[email protected]>

This ensures that shared object members are not modified by any thread.

Signed-off-by: Peter Colberg <[email protected]>