[test-suite] Propagate LDFLAGS variable to executable's LINK_FLAGS property

[tra]

Summary

... which is better match for LDFLAGS which may have options other than -l that should appear on linker command line earlier.

[MatzeB]

We had r703aad1d specifically because people needed the -l flags to come after the object files. What sort of flags need to come earlier?

[MatzeB]

In D19424#409314, @MatzeB wrote:

We had r703aad1d specifically because people needed the -l flags to come after the object files. What sort of flags need to come earlier?

I mean r263235 :)

[tra]

In D19424#409314, @MatzeB wrote:

We had r703aad1d specifically because people needed the -l flags to come after the object files. What sort of flags need to come earlier?

Good point.

I was porting some non-cmake build into the test-suite and wanted to arrange linker flags just so with one object linked before .o files built by cmake from sources. I've figured out a way to do what I wanted using standard cmake features since then, so I don't depend on this change.

cmake/modules/SingleMultiSource.cmake

macro(append_target_flags propertyname target)
   endif()
 endmacro()
 
 macro(append_compile_flags target)
   append_target_flags(COMPILE_FLAGS ${target} ${ARGN})
 endmacro()
 
 macro(append_link_flags target)
-  append_target_flags(LINK_LIBRARIES ${target} ${ARGN})
+  append_target_flags(LINK_FLAGS ${target} ${ARGN})
 endmacro()
 
 # Traditionally CMakeLists.txt files would set RUN_OPTIONS, STDIN_FILENAME,
 # SMALL_PROBLEM_SIZE, HASH_PROGRAM_OUTPUT, etc.
 # Create llvm_test_run() and llvm_test_verify() invocation for that.
 function(llvm_test_traditional testfile executable name)
   if(DEFINED STDIN_FILENAME)
     list(APPEND RUN_OPTIONS "< ${STDIN_FILENAME}")