[UNIKRAFT/LIBMIMALLOC PATCH v2] Initial port of libmimalloc

[Hugo Lefeuvre <hugo.lefeuvre@xxxxxxxxx>]

Hi,

this is the initial port of the Mimalloc [0] general-purpose memory allocator
for Unikraft as an external library.

Changes since v1:
 - add missing Signed-off line
 - fix errors/warnings reported by checkpatch
 - rename compile guards in include/uk/tlsf.h
 - add missing #include to main-tree.patch
 - fix typos in Makefile.uk copyright header

regards,
Hugo

[0] https://microsoft.github.io/mimalloc/

Hugo Lefeuvre (1):
  Initial port of mimalloc to Unikraft