pw_libc: Use .test convention

Change-Id: I36f04d289e32714a32ac04a86b53590778e90bc1
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/171793
Original-Reviewed-by: Armando Montanez <amontanez@google.com>
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/llvm-integration/+/235127
Commit-Queue: Prabhu Karthikeyan Rajasekaran <prabhukr@google.com>
Reviewed-by: Keir Mierle <keir@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/pw_libc/BUILD.gn b/pw_libc/BUILD.gn
index a8ee6bb..ccaf1fa 100644
--- a/pw_libc/BUILD.gn
+++ b/pw_libc/BUILD.gn
@@ -148,12 +148,12 @@
 
   pw_test_group("llvm_libc_tests") {
     tests = [
-      ":ctype_tests",
-      ":math_tests",
-      ":stdio_tests",
-      ":stdlib_tests",
-      ":string_tests",
-      ":time_tests",
+      ":ctype.test",
+      ":math.test",
+      ":stdio.test",
+      ":stdlib.test",
+      ":string.test",
+      ":time.test",
     ]
   }
 } else {
diff --git a/third_party/llvm_libc/llvm_libc.gni b/third_party/llvm_libc/llvm_libc.gni
index fea2509..0636df7 100644
--- a/third_party/llvm_libc/llvm_libc.gni
+++ b/third_party/llvm_libc/llvm_libc.gni
@@ -109,7 +109,7 @@
     }
   }
 
-  pw_test("${source_set_target_name}_tests") {
+  pw_test("${source_set_target_name}.test") {
     _dir = "$dir_pw_third_party_llvm_libc/test/src/$source_set_target_name"
 
     # This might not be used if all test functions are in no_test_functions