Introduce kernel module support for i386, x86-64 and arm

Signed-off-by: Chang Lan <changlan9@gmail.com>
Signed-off-by: Junjie Mao <eternal.n08@gmail.com>
Fix a case expression issue in uCore_test

Signed-off-by: Chang Lan <changlan9@gmail.com>
Signed-off-by: Junjie Mao <eternal.n08@gmail.com>
Merge commit '479f2e6' at https://github.com/TurfKids/ucore_plus.git

Conflicts:
	ucore/src/kern-ucore/glue-ucore/libs/unistd.h
	ucore/src/libs-user-ucore/common/unistd.h
	ucore/src/libs-user-ucore/syscall.c

Signed-off-by: Junjie Mao <eternal.n08@gmail.com>
Add Linux indent script and a goal to indent all C files

Some file are not suitable to be indented by the tool for one of the
following reasions:

  * Containing assembly (or inline assembly) code
  * Copied from other sources with different code style

These files should be listed in the indent-whitelist. They'll then be
excluded in 'make indent' process.

Signed-off-by: Junjie Mao <eternal.n08@gmail.com>
Apply the indent tool

Signed-off-by: Junjie Mao <eternal.n08@gmail.com>