zig build system: change target, compilation, and module APIs

Introduce the concept of "target query" and "resolved target". A target
query is what the user specifies, with some things left to default. A
resolved target has the default things discovered and populated.
In the future, std.zig.CrossTarget will be rename to std.Target.Query.
Introduces `std.Build.resolveTargetQuery` to get from one to the other.

The concept of `main_mod_path` is gone, no longer supported. You have to
put the root source file at the module root now.

* remove deprecated API
* update build.zig for the breaking API changes in this branch
* move std.Build.Step.Compile.BuildId to std.zig.BuildId
* add more options to std.Build.ExecutableOptions, std.Build.ObjectOptions,
  std.Build.SharedLibraryOptions, std.Build.StaticLibraryOptions, and
  std.Build.TestOptions.
* remove `std.Build.constructCMacro`. There is no use for this API.
* deprecate `std.Build.Step.Compile.defineCMacro`. Instead,
  `std.Build.Module.addCMacro` is provided.
  - remove `std.Build.Step.Compile.defineCMacroRaw`.
* deprecate `std.Build.Step.Compile.linkFrameworkNeeded`
  - use `std.Build.Module.linkFramework`
* deprecate `std.Build.Step.Compile.linkFrameworkWeak`
  - use `std.Build.Module.linkFramework`
* move more logic into `std.Build.Module`
* allow `target` and `optimize` to be `null` when creating a Module.
  Along with other fields, those unspecified options will be inherited
  from parent `Module` when inserted into an import table.
* the `target` field of `addExecutable` is now required. pass `b.host`
  to get the host target.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 296b300f8d..7831a58840 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -30,7 +30,6 @@ const fatal = @import("main.zig").fatal;
 const clangMain = @import("main.zig").clangMain;
 const Module = @import("Module.zig");
 const InternPool = @import("InternPool.zig");
-const BuildId = std.Build.CompileStep.BuildId;
 const Cache = std.Build.Cache;
 const c_codegen = @import("codegen/c.zig");
 const libtsan = @import("libtsan.zig");
@@ -910,7 +909,7 @@ pub const InitOptions = struct {
     linker_print_map: bool = false,
     linker_opt_bisect_limit: i32 = -1,
     each_lib_rpath: ?bool = null,
-    build_id: ?BuildId = null,
+    build_id: ?std.zig.BuildId = null,
     disable_c_depfile: bool = false,
     linker_z_nodelete: bool = false,
     linker_z_notext: bool = false,