breaking changes to zig build API and improved caching

 * in Zig build scripts, getOutputPath() is no longer a valid function
   to call, unless setOutputDir() was used, or within a custom make()
   function. Instead there is more convenient API to use which takes
   advantage of the caching system. Search this commit diff for
   `exe.run()` for an example.
 * Zig build by default enables caching. All build artifacts will go
   into zig-cache. If you want to access build artifacts in a convenient
   location, it is recommended to add an `install` step. Otherwise
   you can use the `run()` API mentioned above to execute programs
   directly from their location in the cache. Closes #330.
   `addSystemCommand` is available for programs not built with Zig
   build.
 * Please note that Zig does no cache evicting yet. You may have to
   manually delete zig-cache directories periodically to keep disk
   usage down. It's planned for this to be a simple Least Recently
   Used eviction system eventually.
 * `--output`, `--output-lib`, and `--output-h` are removed. Instead,
   use `--output-dir` which defaults to the current working directory.
   Or take advantage of `--cache on`, which will print the main output
   path to stdout, and the other artifacts will be in the same directory
   with predictable file names. `--disable-gen-h` is available when
   one wants to prevent .h file generation.
 * `@cImport` is always independently cached now. Closes #2015.
   It always writes the generated Zig code to disk which makes debug
   info and compile errors better. No more "TODO: remember C source
   location to display here"
 * Fix .d file parsing. (Fixes the MacOS CI failure)
 * Zig no longer creates "temporary files" other than inside a
   zig-cache directory.

This breaks the CLI API that Godbolt uses. The suggested new invocation
can be found in this commit diff, in the changes to `test/cli.zig`.

2 files changed, 3 insertions, 8 deletions

diff --git a/test/standalone/load_dynamic_library/build.zig b/test/standalone/load_dynamic_library/build.zig
index 2d47a893f2..109c742c6f 100644
--- a/test/standalone/load_dynamic_library/build.zig
+++ b/test/standalone/load_dynamic_library/build.zig
@@ -9,12 +9,8 @@ pub fn build(b: *Builder) void {
     const main = b.addExecutable("main", "main.zig");
     main.setBuildMode(opts);
 
-    const run = b.addCommand(".", b.env_map, [][]const u8{
-        main.getOutputPath(),
-        lib.getOutputPath(),
-    });
-    run.step.dependOn(&lib.step);
-    run.step.dependOn(&main.step);
+    const run = main.run();
+    run.addArtifactArg(lib);
 
     const test_step = b.step("test", "Test the program");
     test_step.dependOn(&run.step);
diff --git a/test/standalone/pkg_import/build.zig b/test/standalone/pkg_import/build.zig
index e0b3885dc3..7529d106f9 100644
--- a/test/standalone/pkg_import/build.zig
+++ b/test/standalone/pkg_import/build.zig
@@ -9,8 +9,7 @@ pub fn build(b: *Builder) void {
     exe.setBuildMode(b.standardReleaseOptions());
     exe.setBuildMode(b.standardReleaseOptions());
 
-    const run = b.addCommand(".", b.env_map, [][]const u8{exe.getOutputPath()});
-    run.step.dependOn(&exe.step);
+    const run = exe.run();
 
     const test_step = b.step("test", "Test it");
     test_step.dependOn(&run.step);