Revert "Fix HAVE_PTHREAD_CONDATTR_SETCLOCK detection on Android (#58701)" (#58755)

This reverts commit a6d9e63.

Author: ViktorHofer

src/libraries/Native/Unix/configure.cmake

@@ -60,7 +60,7 @@ endif()
 # Older CMake versions (3.8) do not assign the result of their tests, causing unused-value errors
 # which are not distinguished from the test failing. So no error for that one.
 # For clang-5.0 avoid errors like "unused variable 'err' [-Werror,-Wunused-variable]".
-set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wno-error=unused-value -Wno-error=unused-variable -Wno-error=builtin-requires-header")
+set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror -Wno-error=unused-value -Wno-error=unused-variable")
 
 # Apple platforms like macOS/iOS allow targeting older operating system versions with a single SDK,
 # the mere presence of a symbol in the SDK doesn't tell us whether the deployment target really supports it.
@@ -671,16 +671,7 @@ check_symbol_exists(
     time.h
     HAVE_CLOCK_GETTIME_NSEC_NP)
 
-check_library_exists(pthread pthread_create "" HAVE_LIBPTHREAD)
-check_library_exists(c pthread_create "" HAVE_PTHREAD_IN_LIBC)
-
-if (HAVE_LIBPTHREAD)
-  set(PTHREAD_LIBRARY pthread)
-elseif (HAVE_PTHREAD_IN_LIBC)
-  set(PTHREAD_LIBRARY c)
-endif()
-
-check_library_exists(${PTHREAD_LIBRARY} pthread_condattr_setclock "" HAVE_PTHREAD_CONDATTR_SETCLOCK)
+check_library_exists(pthread pthread_condattr_setclock "" HAVE_PTHREAD_CONDATTR_SETCLOCK)
 
 check_symbol_exists(
     futimes