OpenMP flags not added if CXX is set to an absolute path

[EmilyBourne]

On supercomputers it is common for compiler paths to be set automatically when modules are loaded. They are usually set to an absolute path in case there are multiple versions of the same compiler installed.

The Makefile does not take this into consideration when deciding which flags to use:

hptt/Makefile

Lines 4 to 10 in 9425386

	ifeq ($(CXX),icpc)
	CXX_FLAGS += -qopenmp -xhost
	else
	ifeq ($(CXX),g++)
	CXX_FLAGS += -fopenmp -march=native
	else
	ifeq ($(CXX),clang++)

as a result OpenMP flags are not added. A similar problem would occur if the compiler was set to a specific version (e.g. g++-13). The Makefile should probably use $(findstring find,in) instead to avoid such errors

[EmilyBourne]

I am happy to create a PR to fix this, but I am not sure if this repo is maintained?