[Compile] Support build with clang

[yiguolei]

Support build Doris BE with clang

Currently, thirdparty could only be build with GCC

[wangbo]

Maybe provide clang in thrid-party or docker image?
And make build with clang an optional args?

[morningman]

I think this should be an optional choice?

[yiguolei]

No, We should remove GCC HOME env.
User should only define CC and CXX env,
for example
export CC= XXXXXXXXXX
export CXX=xxxxxxxxxxxxxx

We define GCC HOME because bitshuffle's build process depend on GCC_HOME/ld. I will rewrite bitshuffle build method use cmake

[yiguolei]

If we want to build with clang, then we export CC=XXXX/clang and CXX=XXXXXXX/clang++
If we want to build with gcc, then we export CC=xxxx/gcc and CXX=xxxxx/g++

[yiguolei]

Maybe provide clang in thrid-party or docker image? And make build with clang an optional args?

Currently, could only build be with clang, And I don't want it to be an optional args because I think we should use clang as default build tool chain in the future.

[wangbo]

It seems that --clean and incremental compilation is not support in this pr;
Every time I need to clean manually