New import resolution

[lerno]

In dev imports work like this:

1. import foo::bar; will import foo::bar and any sub packages of foo::bar
2. For any package, it will without import be able to access any packages with the same top package name. So foo::bar can access foo::baz::my_function() without an import.

Try it out. Currently you're even required to import std::builtin. This will probably change.

[data-man]

import libc;

fn void main()
{
    libc::printf("Hi!\n");
}

$ c3c compile test.c3
$ ls -1 *.o
Why are so many *.o files created?

libc.errno.o
libc.o
math.o
std.array.o
std.atomic.o
std.builtin.o
std.cinterop.o
std.env.o
std.hash.adler32.o
std.hash.crc32.o
std.hash.crc64.o
std.io.o
std.math.o
std.mem.o
std.os.linux.o
std.os.macos.o
std.os.windows.o
std.runtime.o
std.str.o
test.o

[lerno]

Because currently the whole standard library is compiled as well. There are possible optimizations, some which are incompatible

(1) precompile the standard library once as a static library, add it at link time
(2) cache standard library .o files
(3) only compile the part of the standard library that is in use
(4) only codegen the parts of the standard library that is in use

[data-man]

Deleting temporary files after compilation is annoying. My vote is for gcc/clang behavior.
And clean command doesn't work as expected.

[lerno]

Deleting temporary files after compilation is annoying. My vote is for gcc/clang behavior.
And clean command doesn't work as expected.

I added an issue for that. #456