Add Multi library to Circle compiler (#4364)

This works with C++ compiler already

library source and details here: https://gitlab.com/correaa/boost-multi

etc/config/circle.amazon.properties

@@ -26,7 +26,7 @@ compiler.circle128.intelAsm=
 #################################
 #################################
 # Installed libs (See c++.amazon.properties for a scheme of libs group)
-libs=abseil:benchmark:benri:blaze:boost:brigand:catch2:cctz:cmcstl2:cnl:cppcoro:cppitertools:crosscables:ctbignum:ctre:date:dataframe:dlib:doctest:eastl:eigen:enoki:entt:etl:eve:expected_lite:fastor:fmt:glm:gnufs:googletest:gsl:hedley:hfsm:highway:immer:jsoncpp:kiwaku:kumi:kvasir:lager:lexy:libguarded:libuv:llvm:llvmfs:lua:mp-coro:mp-units:namedtype:nanorange:nlohmann_json:nsimd:ofw:openssl:outcome:pegtl:pipes:pugixml:python:rangesv3:raberu:seastar:simde:sol2:spdlog:spy:taojson:tbb:tomlplusplus:trompeloeil:tts:type_safe:unifex:vcl:xsimd:xtensor:xtl:ztdtext:zug
+libs=abseil:benchmark:benri:blaze:boost:bmulti:brigand:catch2:cctz:cmcstl2:cnl:cppcoro:cppitertools:crosscables:ctbignum:ctre:date:dataframe:dlib:doctest:eastl:eigen:enoki:entt:etl:eve:expected_lite:fastor:fmt:glm:gnufs:googletest:gsl:hedley:hfsm:highway:immer:jsoncpp:kiwaku:kumi:kvasir:lager:lexy:libguarded:libuv:llvm:llvmfs:lua:mp-coro:mp-units:namedtype:nanorange:nlohmann_json:nsimd:ofw:openssl:outcome:pegtl:pipes:pugixml:python:rangesv3:raberu:seastar:simde:sol2:spdlog:spy:taojson:tbb:tomlplusplus:trompeloeil:tts:type_safe:unifex:vcl:xsimd:xtensor:xtl:ztdtext:zug
 
 libs.abseil.name=Abseil
 libs.abseil.versions=trunk
@@ -111,6 +111,13 @@ libs.boost.versions.175.path=/opt/compiler-explorer/libs/boost_1_75_0
 libs.boost.versions.176.version=1.76.0
 libs.boost.versions.176.path=/opt/compiler-explorer/libs/boost_1_76_0
 
+libs.bmulti.name=B-Multi
+libs.bmulti.url=https://gitlab.com/correaa/boost-multi
+libs.bmulti.versions=trunk
+libs.bmulti.description=Modern C++ (and Circle) multidimensional arrays
+libs.bmulti.versions.trunk.version=trunk
+libs.bmulti.versions.trunk.path=/opt/compiler-explorer/libs/bmulti/trunk/include
+
 libs.brigand.name=Brigand
 libs.brigand.versions=trunk:130
 libs.brigand.url=https://github.com/edouarda/brigand