Issue with the Jacobi algorithm when using llvm-main

[breyerml]

When using the llvm-main compiler, compiling the Jacobi example results in:

clang -O3 -fopenmp --offload-arch=sm_75 -DUSE_ALLOCATE=1 -o jac_solv jac_solv.o mm_utils.o 
/usr/bin/ld: jac_solv.o: undefined reference to symbol 'sqrt@@GLIBC_2.2.5'
/usr/bin/ld: /lib/x86_64-linux-gnu/libm.so.6: error adding symbols: DSO missing from command line
/shared/llvm-main/bin/clang-linker-wrapper: error: 'ld' failed
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [makefile:16: jac_solv] Error 1