cmake only works with make as generator

[larseggert]

Describe the bug

The cmake build setup only seems to work with make as a generator and not, for example, with ninja.

Steps to reproduce the behavior

# mkdir build && cd build && cmake -GNinja ..
-- Source Dir: /Users/lars/Documents/Code/msquic
-- Host System name: Darwin
-- Setting policy 0091
-- The C compiler identification is AppleClang 11.0.3.11030032
-- The CXX compiler identification is AppleClang 11.0.3.11030032
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ - works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- System name: Darwin
-- System version: 19.5.0
-- Platform version:
-- Disabling events and logging
-- Disabling session resumption support
-- Disabling 0-RTT support
-- Configuring for OpenSSL
-- Configuring done
-- Generating done
CMake Error:
  Running
   '/usr/local/bin/ninja' '-C' '/Users/lars/Documents/Code/msquic/Debug' '-t' 'cleandead'
  failed with:
   ninja: error: build.ninja:84: bad $-escape (literal $ must be written as $$)
CMake Error:
  Running
   '/usr/local/bin/ninja' '-C' '/Users/lars/Documents/Code/msquic/Debug' '-t' 'recompact'
  failed with:
   ninja: error: build.ninja:84: bad $-escape (literal $ must be written as $$)
CMake Generate step failed.  Build files cannot be regenerated correctly.```

Expected vs actual behavior

Expect the build to work.

Fixes

The error above can be removed by removing the -j$(nproc) part from the add_custom_command that builds openssl. But then the error becomes:

# ninja
ninja: error: 'openssl/lib/libssl.a', needed by 'bin/Release/libmsquic.dylib', missing and no known rule to make it

So there are some additional issues.

[ThadHouse]

This was broken again by #569. Once we can fix that, I'll look into onboarding a Ninja build into our CI to make sure this stays working.

[ThadHouse]

Fixed again by #579 and we now run a build in ninja to ensure things stay working.