Patch dlopen() to allow direct paths to all required libs

diff --git a/cairocffi/__init__.py b/cairocffi/__init__.py
index f917d90..31dab12 100644
--- a/cairocffi/__init__.py
+++ b/cairocffi/__init__.py
@@ -22,6 +22,14 @@ VERSION = __version__ = '1.7.1'
 version = '1.17.2'
 version_info = (1, 17, 2)
 
+# Use hardcoded soname, because ctypes.util use gcc/objdump which shouldn't be
+# required for runtime
+_LIBS = {
+    'cairo': '@cairo@/lib/libcairo@ext@',
+    'glib-2.0': '@glib@/lib/libglib-2.0@ext@',
+    'gobject-2.0': '@glib@/lib/libgobject-2.0@ext@',
+    'gdk_pixbuf-2.0': '@gdk_pixbuf@/lib/libgdk_pixbuf-2.0@ext@',
+}
 
 # Python 3.8 no longer searches for DLLs in PATH, so we can add everything in
 # CAIROCFFI_DLL_DIRECTORIES manually. Note that unlike PATH, add_dll_directory
@@ -36,26 +44,14 @@ if dll_directories and hasattr(os, 'add_dll_directory'):
 
 def dlopen(ffi, library_names, filenames):
     """Try various names for the same library, for different platforms."""
-    exceptions = []
-
     for library_name in library_names:
-        library_filename = find_library(library_name)
-        if library_filename:
-            filenames = (library_filename, *filenames)
-        else:
-            exceptions.append(
-                'no library called "{}" was found'.format(library_name))
-
-    for filename in filenames:
-        try:
-            return ffi.dlopen(filename)
-        except OSError as exception:  # pragma: no cover
-            exceptions.append(exception)
-
-    error_message = '\n'.join(  # pragma: no cover
-        str(exception) for exception in exceptions)
-    raise OSError(error_message)  # pragma: no cover
+        path = _LIBS.get(library_name, None)
+        if path:
+            lib = ffi.dlopen(path)
+            if lib:
+                return lib
 
+    raise OSError("dlopen() failed to load a library: %s as %s" % (library_name, path))
 
 cairo = dlopen(
     ffi, ('cairo-2', 'cairo', 'libcairo-2'),