Finite Field support #439

Job	Run time
ubuntu-latest\|debug\|--enable-mcsat\|CC=gcc CXX=g++	8m 26s
ubuntu-latest\|debug\|--enable-mcsat\|CC=clang CXX=clang++	8m 39s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=gcc CXX=g++	4m 5s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=clang CXX=clang++	4m 13s
ubuntu-latest\|release\|--enable-mcsat\|CC=gcc CXX=g++	5m 15s
ubuntu-latest\|release\|--enable-mcsat\|CC=clang CXX=clang++	5m 28s
ubuntu-latest\|release\|--enable-thread-safety\|CC=gcc CXX=g++	2m 18s
ubuntu-latest\|release\|--enable-thread-safety\|CC=clang CXX=clang++	2m 45s
ubuntu-latest\|gcov\|--enable-mcsat\|CC=gcc CXX=g++	7m 52s
ubuntu-latest\|debug\|--enable-thread-safety --enable-mcsat\|CC=gcc CXX=g++	8m 32s
	57m 33s

Provide feedback