Prevector Quick Destruct

Summary:

• Add prevector destructor benchmark
• Only call clear on prevector if it isn't trivially destructible and don't loop in clear

This is a backport of Core PR9505

Test Plan:

make
./src/bench/bench_bitcoin

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: jasonbcox, teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1843