make zig build test check for conforming formatting

There was already `zig build test-fmt` but now `zig build test` depends
on that one.

The CI scripts no longer need explicit logic since they already do
`zig build test`.

build.zig

@@ -428,18 +428,21 @@ pub fn build(b: *std.Build) !void {
     }
     const optimization_modes = chosen_opt_modes_buf[0..chosen_mode_index];
 
-    const fmt_include_paths = &.{ "doc", "lib", "src", "test", "tools", "build.zig" };
+    const fmt_include_paths = &.{ "lib", "src", "test", "tools", "build.zig", "build.zig.zon" };
     const fmt_exclude_paths = &.{"test/cases"};
     const do_fmt = b.addFmt(.{
         .paths = fmt_include_paths,
         .exclude_paths = fmt_exclude_paths,
     });
+    b.step("fmt", "Modify source files in place to have conforming formatting").dependOn(&do_fmt.step);
 
-    b.step("test-fmt", "Check source files having conforming formatting").dependOn(&b.addFmt(.{
+    const check_fmt = b.step("test-fmt", "Check source files having conforming formatting");
+    check_fmt.dependOn(&b.addFmt(.{
         .paths = fmt_include_paths,
         .exclude_paths = fmt_exclude_paths,
         .check = true,
     }).step);
+    test_step.dependOn(check_fmt);
 
     const test_cases_step = b.step("test-cases", "Run the main compiler test cases");
     try tests.addCases(b, test_cases_step, test_filters, check_case_exe, target, .{
@@ -534,9 +537,6 @@ pub fn build(b: *std.Build) !void {
 
     try addWasiUpdateStep(b, version);
 
-    b.step("fmt", "Modify source files in place to have conforming formatting")
-        .dependOn(&do_fmt.step);
-
     const update_mingw_step = b.step("update-mingw", "Update zig's bundled mingw");
     const opt_mingw_src_path = b.option([]const u8, "mingw-src", "path to mingw-w64 source directory");
     const update_mingw_exe = b.addExecutable(.{

ci/aarch64-linux-debug.sh

@@ -49,13 +49,6 @@ unset CXX
 
 ninja install
 
-# TODO: move this to a build.zig step (check-fmt)
-echo "Looking for non-conforming code formatting..."
-stage3-debug/bin/zig fmt --check .. \
-  --exclude ../test/cases/ \
-  --exclude ../doc/ \
-  --exclude ../build-debug
-
 # simultaneously test building self-hosted without LLVM and with 32-bit arm
 stage3-debug/bin/zig build \
   -Dtarget=arm-linux-musleabihf \

ci/aarch64-linux-release.sh

@@ -49,13 +49,6 @@ unset CXX
 
 ninja install
 
-# TODO: move this to a build.zig step (check-fmt)
-echo "Looking for non-conforming code formatting..."
-stage3-release/bin/zig fmt --check .. \
-  --exclude ../test/cases/ \
-  --exclude ../doc/ \
-  --exclude ../build-release
-
 # simultaneously test building self-hosted without LLVM and with 32-bit arm
 stage3-release/bin/zig build \
   -Dtarget=arm-linux-musleabihf \

ci/x86_64-linux-debug.sh

@@ -57,13 +57,6 @@ unset CXX
 
 ninja install
 
-# TODO: move this to a build.zig step (check-fmt)
-echo "Looking for non-conforming code formatting..."
-stage3-debug/bin/zig fmt --check .. \
-  --exclude ../test/cases/ \
-  --exclude ../doc/ \
-  --exclude ../build-debug
-
 # simultaneously test building self-hosted without LLVM and with 32-bit arm
 stage3-debug/bin/zig build \
   -Dtarget=arm-linux-musleabihf \

ci/x86_64-linux-release.sh

@@ -57,14 +57,6 @@ unset CXX
 
 ninja install
 
-# TODO: move this to a build.zig step (check-fmt)
-echo "Looking for non-conforming code formatting..."
-stage3-release/bin/zig fmt --check .. \
-  --exclude ../test/cases/ \
-  --exclude ../doc/ \
-  --exclude ../build-debug \
-  --exclude ../build-release
-
 # simultaneously test building self-hosted without LLVM and with 32-bit arm
 stage3-release/bin/zig build \
   -Dtarget=arm-linux-musleabihf \