egl: Add _eglSearchPathForEach.

The function can be used by a driver to check each search path of EGL.

src/egl/main/egldriver.c

@@ -652,6 +652,21 @@ _eglInitDriverFallbacks(_EGLDriver *drv)
 }
 
 
+/**
+ * Invoke a callback function on each EGL search path.
+ *
+ * The first argument of the callback function is the name of the search path.
+ * The second argument is the length of the name.
+ */
+void
+_eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
+                      void *callback_data)
+{
+   const char *search_path = _eglGetSearchPath();
+   _eglPreloadForEach(search_path, callback, callback_data);
+}
+
+
 /**
  * Set the probe cache at the given key.
  *

src/egl/main/egldriver.h

@@ -88,6 +88,11 @@ PUBLIC void
 _eglInitDriverFallbacks(_EGLDriver *drv);
 
 
+PUBLIC void
+_eglSearchPathForEach(EGLBoolean (*callback)(const char *, size_t, void *),
+                      void *callback_data);
+
+
 PUBLIC void
 _eglSetProbeCache(EGLint key, const void *val);