[test-suite] There is no need to check for name clashes explicitly.

[tra]

Summary

cmake_minimum_required(VERSION 3.2) sets CMP0002 policy to NEW
which will produce an error when someone attempts to create a
new target with the same name.

When that happens llvm_target_prefix() can be used to ensure unique
names for targets within.

[MatzeB]

This looks good. Thanks.

[MatzeB]

Actually I think getting and setting the registered_executables is obsolete as well without the explicit check.

[tra]

Removed registered_executables property.

[MatzeB]

Still good, yay for simpler code!

[tra]

Committed in r267461

cmake/modules/SingleMultiSource.cmake

function(llvm_target_prefix prefix)
   else()
     set(TARGET_PREFIX "" PARENT_SCOPE)
   endif()
 endfunction()
 
 # Given a source file name after which a test should be named, create a unique
 # name for the test. Usually this is just the source file with the suffix
 # stripped, and ${TARGET_PREFIX} prepended.
-set_property(GLOBAL PROPERTY registered_executables)
 function(get_unique_exe_name new_name main_src)
-  get_property(registered_executables GLOBAL PROPERTY registered_executables)
-
   string(REGEX REPLACE ".[cp]+$" "" path ${main_src})
   get_filename_component(name ${path} NAME )
-  set(name "${TARGET_PREFIX}${name}")
-
-  list(FIND registered_executables ${name} name_idx)
-
-  if(${name_idx} EQUAL -1)
-    set(${new_name} ${name} PARENT_SCOPE)
-    set_property(GLOBAL APPEND PROPERTY registered_executables ${name})
-    return()
-  endif()
 
-  message(FATAL_ERROR "Duplicate executable name!"
-    "Please set unique prefix with llvm_target_prefix().")
+  set(${new_name} "${TARGET_PREFIX}${name}" PARENT_SCOPE)
 endfunction()
 
 # Add flags to a cmake target property.
 macro(append_target_flags propertyname target)
   if(NOT "${ARGN}" STREQUAL "")
     get_target_property(old_flags ${target} ${propertyname})
     if(${old_flags} STREQUAL "old_flags-NOTFOUND")
       set(old_flags)