Enable CMP0074 to allow `${pkg}_ROOT`, especially for LLVM_ROOT (#3713)
Enable CMP0074 to allow `${pkg}_ROOT`, especially for LLVM_ROOT (#3713)

set CMP0074 to allow the use of `LLVM_ROOT` env var
iovisor/bcc,brendangregg/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc