* [TD-3973]<feature>: add jemalloc as submodule.

* add macro definitions in cmake.

* [TD-3973]<feature>: use jemalloc.

build works as following instructions:

cmake .. -DJEMALLOC_ENABLED=true

make

* fix jemalloc at tag 5.2.1

* link jemalloc works.

* make install works.

* support jemalloc in release.sh.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-3913]<fix>: mips compile support.

* [TD-3913]<fix>: mips64 support.

* fix osSignal.c

* fix tcrc32c.c

* fix cmake.

* fix osInc.h

* fix gcc 4.8 compile error.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-3913]<fix>: mips compile support.

* [TD-3912]<fix>: support mips64 compile.

add mips64 header file and modify tcrc32c.c for mips64.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

2. tsem_xxx for mac

2. for the sake of SIGALRM used in the base code, add taos_block_sigalrm and so forth
3. TODO: getaddrinfo would block a few unnecessary seconds when host ~ *.local
         better give warning/suggestion message to user, or just bypass getaddrinfo
         and fail the function