message: fix makefiles in case MPI is turned on
diff: @@ -7,16 +7,16 @@ CMDSTAN_MAIN := src/cmdstan/main.cpp
  $(MODEL_PCH) : $(MODEL_HEADER)
  @echo 'Compiling pre-compiled header'
  - $(COMPILE.cc) -O$O $(MODEL_HEADER) -o $@
  + $(COMPILE.cc) -O$O $(CXXFLAGS_MPI) $(MODEL_HEADER) -o $@
  .PRECIOUS: %.hpp %.o
  $(patsubst %.stan,%,$(wildcard $(addsuffix .stan,$(MAKECMDGOALS)))) : %$(EXE) : %.hpp %.stan bin/stanc$(EXE) bin/stansummary$(EXE) bin/diagnose$(EXE) $(LIBMPI) $(LIBSUNDIALS) $(MODEL_PCH)
  @echo ''
  @echo '--- Linking C++ model ---'
  ifneq (,$(findstring allow_undefined,$(STANCFLAGS)))
  - $(LINK.cc) $(CMDSTAN_MAIN) $(if $(filter $(CC_TYPE),clang++),-include-pch $(MODEL_PCH)) -O$O $(OUTPUT_OPTION) -include $< -include $(USER_HEADER) $(LIBSUNDIALS) $(LIBMPI)
  + $(LINK.cc) $(CMDSTAN_MAIN) $(if $(filter $(CC_TYPE),clang++),-include-pch $(MODEL_PCH)) -O$O $(OUTPUT_OPTION) -include $< -include $(USER_HEADER) $(LIBSUNDIALS) $(CXXFLAGS_MPI) $(LIBMPI) $(LDFLAGS_MPI)
  else
  - $(LINK.cc) $(CMDSTAN_MAIN) $(if $(filter $(CC_TYPE),clang++),-include-pch $(MODEL_PCH)) -O$O $(OUTPUT_OPTION) -include $< $(LIBSUNDIALS) $(LIBMPI)
  + $(LINK.cc) $(CMDSTAN_MAIN) $(if $(filter $(CC_TYPE),clang++),-include-pch $(MODEL_PCH)) -O$O $(OUTPUT_OPTION) -include $< $(LIBSUNDIALS) $(CXXFLAGS_MPI) $(LIBMPI) $(LDFLAGS_MPI)
  endif
  .PRECIOUS: %.hpp
  