build: make test-incremental respect -Dtest-filter

build.zig

@@ -743,7 +743,7 @@ pub fn build(b: *std.Build) !void {
     }
 
     const test_incremental_step = b.step("test-incremental", "Run the incremental compilation test cases");
-    try tests.addIncrementalTests(b, test_incremental_step);
+    try tests.addIncrementalTests(b, test_incremental_step, test_filters);
     if (!skip_test_incremental) test_step.dependOn(test_incremental_step);
 
     if (tests.addLibcTests(b, .{

test/tests.zig

@@ -2682,7 +2682,7 @@ pub fn addDebuggerTests(b: *std.Build, options: DebuggerContext.Options) ?*Step
     return step;
 }
 
-pub fn addIncrementalTests(b: *std.Build, test_step: *Step) !void {
+pub fn addIncrementalTests(b: *std.Build, test_step: *Step, test_filters: []const []const u8) !void {
     const io = b.graph.io;
 
     const incr_check = b.addExecutable(.{
@@ -2701,6 +2701,10 @@ pub fn addIncrementalTests(b: *std.Build, test_step: *Step) !void {
     while (try it.next(io)) |entry| {
         if (entry.kind != .file) continue;
 
+        for (test_filters) |test_filter| {
+            if (std.mem.indexOf(u8, entry.path, test_filter)) |_| break;
+        } else if (test_filters.len > 0) continue;
+
         const run = b.addRunArtifact(incr_check);
         run.setName(b.fmt("incr-check '{s}'", .{entry.basename}));