Update build-tools to ab/3754978

bpfmt changed because we've updated to go1.8

makeparallel includes my signal changes to prevent duplicate signals

Bug: 35214134
Test: send ctrl-c with soong_ui, ensure that only one signal is
received, and that make waits for soong_ui to exit before continuing.

Change-Id: Ibe6dfba9448b132935cad798ec068cb7b8f7fed0