Report library load errors in debug builds.

Change-Id: I24e63b15ad74fb86ecfe839f543800c2140c09d9

runtime/hsa-runtime/core/util/lnx/os_linux.cpp

@@ -67,6 +67,7 @@ static_assert(sizeof(Thread) == sizeof(pthread_t),
 
 LibHandle LoadLib(std::string filename) {
   void* ret = dlopen(filename.c_str(), RTLD_LAZY);
+  if (ret == nullptr) debug_print("LoadLib(%s) failed: %s\n", filename.c_str(), dlerror());
   return *(LibHandle*)&ret;
 }
 

runtime/hsa-runtime/core/util/utils.h

@@ -98,7 +98,9 @@ static __forceinline unsigned long long int strtoull(const char* str,
 #define PASTE(x, y) PASTE2(x, y)
 
 #ifdef NDEBUG
-#define debug_warning(exp)
+#define debug_warning(exp)                                                                         \
+  do {                                                                                             \
+  } while (false)
 #else
 #define debug_warning(exp)                                                                         \
   do {                                                                                             \