pocl 冗余log信息问题

[zhoujingya]

结合log信息

### Triple: riscv32, CPU: ventus-gpgpu
Warning: the memory at  [0x90000000, 0x90000017] has been realigned
to the 4 KiB page size: [0x90000000, 0x90000FFF]
to allocate at 0x90000000 with 4096 bytes 
to copy to 0x90000000 with 24 bytes
Warning: the memory at  [0x90001000, 0x90001017] has been realigned
to the 4 KiB page size: [0x90001000, 0x90001FFF]
to allocate at 0x90001000 with 4096 bytes 
to copy to 0x90001000 with 24 bytes
Warning: the memory at  [0x90002000, 0x90002017] has been realigned
to the 4 KiB page size: [0x90002000, 0x90002FFF]
to allocate at 0x90002000 with 4096 bytes 
to copy to 0x90000000 with 24 bytes
to copy to 0x90001000 with 24 bytes
to copy to 0x90000000 with 24 bytes
to copy to 0x90001000 with 24 bytes
notice that ventus hasn't support local buffer as argument yet.
Warning: the memory at  [0x90003000, 0x9000300B] has been realigned
to the 4 KiB page size: [0x90003000, 0x90003FFF]
to allocate at 0x90003000 with 4096 bytes 
to copy to 0x90003000 with 12 bytes
to allocate at 0x90004000 with 131072 bytes 
Warning: the memory at  [0x90024000, 0x9002403F] has been realigned
to the 4 KiB page size: [0x90024000, 0x90024FFF]
to allocate at 0x90024000 with 4096 bytes 
to copy to 0x90024000 with 64 bytes

其实以上有很多打印信息是无用信息，是否可以设置一个开关，类似POCL_DEBUG=all这种，控制打印行为，就比如我跑测试时，其实只关注测试成功与否，并不想看这些信息，看信息我会去log文件看是吧，测试出错的时候，我才会想看到具体的程序报错，其他的控制台信息我们是不会关心的

[yangzexia]

[log] Log信息太过琐碎的问题 #11