python-gdb.py: get C types at runtime

Issue #26799: Fix python-gdb.py: don't get once C types when the Python code
is loaded, but get C types on demande. The C types can change if
python-gdb.py is loaded before the Python executable.

Patch written by Thomas Ilsche.
diff --git a/Misc/ACKS b/Misc/ACKS
index 6c01880..6f4bfdb 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -648,6 +648,7 @@
 Mihai Ibanescu
 Ali Ikinci
 Aaron Iles
+Thomas Ilsche
 Lars Immisch
 Bobby Impollonia
 Naoki Inada