Merge remote-tracking branch 'origin/master' into ast-memory-layout

Conflicts:
 * lib/std/zig/ast.zig
 * lib/std/zig/parse.zig
 * lib/std/zig/parser_test.zig
 * lib/std/zig/render.zig
 * src/Module.zig
 * src/zir.zig

I resolved some of the conflicts by reverting a small portion of
@tadeokondrak's stage2 logic here regarding `callconv(.Inline)`.
It will need to get reworked as part of this branch.

lib/std/std.zig

@@ -78,6 +78,7 @@ pub const testing = @import("testing.zig");
 pub const time = @import("time.zig");
 pub const unicode = @import("unicode.zig");
 pub const valgrind = @import("valgrind.zig");
+pub const wasm = @import("wasm.zig");
 pub const zig = @import("zig.zig");
 pub const start = @import("start.zig");