Conflicts:
* build.zig
* src/Compilation.zig
* src/codegen/spirv/spec.zig
* src/link/SpirV.zig
* test/stage2/darwin.zig
- this one might be problematic; start.zig looks for `main` in the
root source file, not `_main`. Not sure why there is an underscore
there in master branch.
* AstGen: emit decl lookup ZIR instructions rather than directly
looking up decls in AstGen. This is necessary because we want to
reuse the same immutable ZIR code for multiple generic instantiations
(and comptime function calls).
* AstGen: fix using members_len instead of fields_len for struct decls.
* structs: the struct_decl ZIR instruction is now also a block. This is
so that the type expressions, default field value expressions, and
alignment expressions can be evaluated in a scope that contains the
decls from the struct namespace itself.
* Add "std" and "builtin" packages to the builtin package.
* Don't try to build glibc, musl, or mingw-w64 when using `-ofmt=c`.
* builtin.zig is generated without `usingnamespace`.
* builtin.zig takes advantage of `std.zig.fmtId` for CPU features.
* A first pass at implementing `usingnamespace`. It's problematic and
should either be deleted, or polished, before merging this branch.
* Sema: allow explicitly specifying the namespace in which to look up
Decls. This is used by `struct_decl` in order to put the decls from
the struct namespace itself in scope when evaluating the type
expressions, default value expressions, and alignment expressions.
* Module: fix `analyzeNamespace` assuming that it is the top-level root
declaration node.
* Sema: implement comptime and runtime cmp operator.
* Sema: implement peer type resolution for enums and enum literals.
* Pull in the changes from master branch:
262e09c482d98a78531c049a18b7f24146fe157f.
* ZIR: complete out simple_ptr_type debug printing
