Fix path to post-processing merge script (#187)

- Path to merge script not found unless user explicitly sources "share/rocprofiler-systems/setup-env.sh" to setup PATHs.
- Instead, let's derive the path when the application loads and use it when executing the helper script
- Rename script to rocprof-sys-merge-output.sh.
- Change install folder to <prefix>/libexec/rocprofiler-systems based on dev-ops feedback.
- Updated PATH variable in the modulefile and source scrtipt.
- For SWDEV-528101

[ROCm/rocprofiler-systems commit: adc66956b0]

projects/rocprofiler-systems/source/bin/rocprof-sys-sample/impl.cpp

@@ -124,9 +124,11 @@ get_initial_environment()
 
     auto _dl_libpath   = get_realpath(get_internal_libpath("librocprof-sys-dl.so"));
     auto _omni_libpath = get_realpath(get_internal_libpath("librocprof-sys.so"));
+    auto _libexecpath  = get_realpath(get_internal_script_path());
 
     update_env(_env, "LD_PRELOAD", _dl_libpath, UPD_APPEND);
     update_env(_env, "LD_LIBRARY_PATH", tim::filepath::dirname(_dl_libpath), UPD_APPEND);
+    update_env(_env, "ROCPROFSYS_SCRIPT_PATH", _libexecpath, UPD_REPLACE);
 
     auto _mode = get_env<std::string>("ROCPROFSYS_MODE", "sampling", false);
 
@@ -136,7 +138,6 @@ get_initial_environment()
     if(!getenv("OMP_TOOL_LIBRARIES"))
         update_env(_env, "OMP_TOOL_LIBRARIES", _dl_libpath, UPD_APPEND);
 #endif
-
     return _env;
 }
 
@@ -150,6 +151,20 @@ get_internal_libpath(const std::string& _lib)
     return rocprofsys::common::join("/", _dir, "..", "lib", _lib);
 }
 
+std::string
+get_internal_script_path(void)
+{
+    auto _exe = std::string_view{ realpath("/proc/self/exe", nullptr) };
+    auto _pos = _exe.find_last_of('/');
+    auto _dir = std::string{ "./" };
+    if(_pos != std::string_view::npos) _dir = _exe.substr(0, _pos);
+
+    auto _script_dir =
+        rocprofsys::common::join("/", _dir, "..", "libexec", "rocprofiler-systems");
+
+    return _script_dir;
+}
+
 void
 print_updated_environment(std::vector<char*> _env)
 {