Upgrade rust/crates/libloading to 0.6.6 am: e4b4c8f5a2 am: bdf1f3062d

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/libloading/+/1517179

Change-Id: I0e03e0a0af1d3267cca780e4b4fbb99140ed436b