Add modular library level build file. #24

Job	Run time
osx (ASAN=off LIBCXX=off CXXFLAGS='-DBOOST_HOF_HAS Job 0, boost, macos-10.15, clang++, 11.7, -DBO...	1s
posix (CLANG_VERSION=3.5 ASAN=on LIBCXX=on Job 1, boost, util-linux g++-4.9 clang-3.5 valgrind, u...	1m 2s
posix (CLANG_VERSION=3.5 ASAN=on LIBCXX=off Job 2, boost, util-linux g++-4.9 clang-3.5 valgrind, ...	1m 16s
posix (CLANG_VERSION=3.8 ASAN=off LIBCXX=on BUILD_EX Job 3, boost, util-linux g++-4.9 clang-3.8 v...	1m 26s
posix (CLANG_VERSION=3.8 ASAN=off LIBCXX=off BUILD_E Job 4, boost, util-linux g++-4.9 clang-3.8 v...	1m 2s
posix (CLANG_VERSION=3.8 ASAN=off LIBCXX=off CXX11=o Job 5, boost, util-linux g++-4.9 clang-3.8 v...	1m 26s
posix (GCC_VERSION=7 ASAN=off LIBCXX=off Job 6, boost, g++-7 valgrind, ubuntu-20.04, ubuntu:16.04...	1m 7s
posix (GCC_VERSION=6 ASAN=off LIBCXX=off Job 7, boost, g++-6 valgrind, ubuntu-20.04, ubuntu:14.04...	1m 6s
posix (GCC_VERSION=5 ASAN=off LIBCXX=off Job 8, boost, g++-5 valgrind, ubuntu-20.04, ubuntu:16.04...	1m 10s
posix (GCC_VERSION=4.9 ASAN=off LIBCXX=off Job 9, boost, g++-4.9 valgrind, ubuntu-20.04, ubuntu:1...	1m 35s
posix (GCC_VERSION=4.8 ASAN=off LIBCXX=off Job 10, boost, g++-4.8 valgrind, ubuntu-20.04, ubuntu:...	1m 16s
posix (GCC_VERSION=4.7 ASAN=off LIBCXX=off Job 11, boost, g++-4.7 valgrind, ubuntu-20.04, ubuntu:...	57s
posix (GCC_VERSION=4.6 ASAN=off LIBCXX=off Job 12, boost, g++-4.6 valgrind, ubuntu-20.04, ubuntu:...	1m 4s
	14m 28s

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