fixup! Import the source code of mimalloc v2.0.9

In preparation for upgrading mimalloc to v2.1.2, let's revert this patch
so that we can start afresh, from a clean slate.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

Makefile

@@ -1334,7 +1334,6 @@ BUILTIN_OBJS += builtin/write-tree.o
 # upstream unnecessarily (making merging in future changes easier).
 THIRD_PARTY_SOURCES += compat/inet_ntop.c
 THIRD_PARTY_SOURCES += compat/inet_pton.c
-THIRD_PARTY_SOURCES += compat/mimalloc/%
 THIRD_PARTY_SOURCES += compat/nedmalloc/%
 THIRD_PARTY_SOURCES += compat/obstack.%
 THIRD_PARTY_SOURCES += compat/poll/%