* standard library knows if it is linking against libc and will
sometimes call libc functions in that case instead of providing
redundant definitions
* fix infinite loop bug when resolving use declarations
* allow calling the same C function from different C imports.
closes#277
* push more logic from compiler to std/bootstrap.zig
* standard library provides way to access errno
closes#274
* fix compile error in standard library for windows
* add implementation of getRandomBytes for windows
previously, we had lazy analysis of top level declarations,
but if a declaration was referenced within a compile-time
if or switch statement, that would still add the top
level declaration to the resolution queue.
now we have a declref ir instruction, which is only resolved
if we analyze the instruction. this takes into account comptime
branching.
closes#270
before, when we initialized a variable by copying the
initialization value, it made the internal const value
references point to a duplicate value, resulting in
a phony duplicate global value being updated instead of
the real on. now the behavior is as expected.
thanks to hoppetosse for pointing out this bug on IRC.
adds compile error when passing pointer that is byte-aligned
at the beginning but not the end to a function expecting
a fully byte aligned pointer
closes#261
* `@truncate` builtin allows casting to the same size integer.
It also performs two's complement casting between signed and
unsigned integers.
* The idiomatic way to convert between bytes and numbers is now
`mem.readInt` and `mem.writeInt` instead of an unsafe cast.
It works at compile time, is safer, and looks cleaner.
* Implicitly casting an array to a slice is allowed only if the
slice is const.
* Constant pointer values know if their memory is from a compile-
time constant value or a compile-time variable.
* Cast from [N]u8 to []T no longer allowed, but [N]u8 to []const T
still allowed.
* Fix inability to pass a mutable pointer to comptime variable at
compile-time to a function and have the function modify the
memory pointed to by the pointer.
* Add the `comptime T: type` parameter back to mem.eql. Prevents
accidentally creating instantiations for arrays.
