polish build.sh, add spasm, mathicgb and their dependent library

[wangyenshu]

This pull request add the following library:

MEMTAILOR, MATHIC, MATHICGB, GIVARO, OPENBLAS, FFLAS-FFPACK, SPASM

and polishes the build.sh. These dyn_modules should be available to Singular-in-Browser:

bigintm syzextra gfanlib customstd staticdemo subsets freealgebra partialgb gitfan interval cohomo loctriv sispasm

For example, LIB "gitfan.lib"; is working now. I have updated the demo at https://wangyenshu.github.io/Singular-wasm/ for debugging.

TODO:

• add "machinelearning Order singmathic" dyn_modules. I had issues with getthing these modules to work, for more details, see the comment section in build.sh
• enable openmp: openmp is now disabled and the file omp.h is used for tricking compilers to compile SPASM into single thread application. Here is a resource for enabling openmp in emscripten: Enabling openmp emscripten-core/emscripten#13892.
• maybe add "-msimd128" for all library? For this pull request, only OpenBLAS, FFLAS-FFPACK, SpaSM and Singular has "-msimd128" enabled.
• polish code
• check if there is any missing functionality

[wangyenshu]

Hello. I just found out that normaliz can be compiled with e-antic, nauty and cocoalib as optionali packages. (see https://github.com/Normaliz/Normaliz) They have not been added to Singular-in-Browser. Are they needed for some functionality of Singular? If so, I will plan to add them.