[libc][NFC] Make thread_detach_test an integration test.

This is simple switch from a unittest to an integration test. It is
being done as a preparatory step to adding TLS support to thread
creation. TLS setup and initialization is tightly coupled with the
loader and hence all thread related tests should be integration tests.

libc/test/integration/src/CMakeLists.txt

@@ -1,3 +1,4 @@
+add_subdirectory(__support)
 add_subdirectory(pthread)
 add_subdirectory(stdlib)
 add_subdirectory(threads)

libc/test/integration/src/__support/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(threads)

libc/test/integration/src/__support/threads/CMakeLists.txt

@@ -3,11 +3,16 @@ if(NOT (TARGET libc.src.__support.threads.thread AND
   return()
 endif()
 
-add_libc_unittest(
+add_libc_integration_test_suite(libc-support-threads-integration-tests)
+
+add_integration_test(
   thread_detach_test
   SUITE
+    libc-support-threads-integration-tests
   SRCS
     thread_detach_test.cpp
+  LOADER
+    libc.loader.linux.crt1
   DEPENDS
     libc.src.__support.threads.mutex
     libc.src.__support.threads.thread

libc/test/integration/src/__support/threads/thread_detach_test.cpp

@@ -1,4 +1,4 @@
-//===-- Unittests for thrd_t ----------------------------------------------===//
+//===-- Tests for thread detach functionality -----------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -8,7 +8,7 @@
 
 #include "src/__support/threads/mutex.h"
 #include "src/__support/threads/thread.h"
-#include "utils/UnitTest/Test.h"
+#include "utils/IntegrationTest/test.h"
 
 __llvm_libc::Mutex mutex(false, false, false);
 
@@ -18,7 +18,7 @@ int func(void *) {
   return 0;
 }
 
-TEST(LlvmLibcTestThreadTest, DetachSimpleTest) {
+void detach_simple_test() {
   mutex.lock();
   __llvm_libc::Thread th;
   th.run(func, nullptr, nullptr, 0);
@@ -32,7 +32,7 @@ TEST(LlvmLibcTestThreadTest, DetachSimpleTest) {
   mutex.unlock();
 }
 
-TEST(LlvmLibcTestThreadTest, DetachCleanupTest) {
+void detach_cleanup_test() {
   mutex.lock();
   __llvm_libc::Thread th;
   ASSERT_EQ(0, th.run(func, nullptr, nullptr, 0));
@@ -49,3 +49,9 @@ TEST(LlvmLibcTestThreadTest, DetachCleanupTest) {
   // resources.
   ASSERT_EQ(th.detach(), int(__llvm_libc::DetachType::CLEANUP));
 }
+
+int main() {
+  detach_simple_test();
+  detach_cleanup_test();
+  return 0;
+}

libc/test/src/__support/CMakeLists.txt

@@ -79,4 +79,3 @@ add_custom_command(TARGET libc_str_to_float_comparison_test
 add_subdirectory(CPP)
 add_subdirectory(File)
 add_subdirectory(OSUtil)
-add_subdirectory(threads)