* build: detect the presence of libgmp before generating Makefile
* depends: add arximboldi/immer@v0.6.2 as a package and add detection
* depends: remove immer from source tree, build using package only
* Drop immer refs from tools
Co-authored-by: UdjinM6 <UdjinM6@users.noreply.github.com>
* Update immer library to current master (0a718d2d76bab6ebdcf43de943bd6c7d2dbfe2f9)
* Temporary fix for alignof(std::max_align_t) on MinGW 32bit builds
See https://github.com/arximboldi/immer/issues/78