cmake: Some improvements using `PROJECT_IS_TOP_LEVEL` variable#1284

Merged

real-or-random merged 3 commits intobitcoin-core:masterfrom hebasto:230420-parent

Apr 27, 2023

+17-3

Commits on Apr 20, 2023

cmake: Emulate PROJECT_IS_TOP_LEVEL for CMake<3.21
hebasto
committed

Commits on Apr 21, 2023

cmake: Make SECP256K1_INSTALL default depend on PROJECT_IS_TOP_LEVEL
hebasto
committed

Commits on Apr 27, 2023

cmake: Include include directory for subtree builds
hebasto
committed