test: cover shared object folder lookup

Add a CMocka suite around the production shared-object path helper and register it in the existing utility test hierarchy.

Cover directory extraction for a resolvable symbol, invalid symbol and buffer arguments, a zero-sized buffer, and an undersized buffer. These cases protect the path contract used by the library-adjacent mapping lookup.

cmake/src/test/util/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_subdirectory(mem)
-add_subdirectory(str)
+add_subdirectory(proc)
+add_subdirectory(str)

cmake/src/test/util/proc/CMakeLists.txt

@@ -0,0 +1,11 @@
+project(test-util-proc)
+message(STATUS "Project " ${PROJECT_NAME})
+
+set(SRC ${PT_ROOT_TEST}/util/proc)
+
+set(SOURCE_FILES
+        ${SRC}/main.c)
+
+add_executable(${PROJECT_NAME} ${SOURCE_FILES})
+
+target_link_libraries(${PROJECT_NAME} cmocka util dl)