Fix undefined misaligned writes

Change-Id: I8ad64babd43c2a692c305f3fa56331edb6d502ee
dlclose confuses LeakSanitizer

Change-Id: I2bebbf1615ddc3619bcc3bf940f70c0967ce8534
external/python3: Fix memory leak in configure check code

...that LeakSanitizer would complain about, causing the check to erroneously fail.

Change-Id: Ieaef38576afd6196d38f395d48fd1bc92b22ddb6