Migrate build system from Intel oneAPI to AMD AOCC/AOCL toolchain

- Add TOOLCHAIN=aocc option with flang/clang++/mpicxx compilers
- Replace Intel flags (-xHost/-fma/-ipo/-qopenmp) with AOCC flags
  (-march=znver5/-ffast-math/-flto/-fopenmp) targeting EPYC 9755
- Replace Intel oneMKL with AMD AOCL (BLIS + libFLAME + amdlibm)
- Replace Intel TBBMALLOC with system jemalloc
- Change MKL-specific headers to standard CBLAS/LAPACKE
  (TwoPunctures.C, gaussj.C)
- Guard TBBMALLOC to Intel toolchain only

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

AMSS_NCKU_source/TwoPunctures.C

@@ -27,7 +27,7 @@ using namespace std;
 #endif
 
 #include "TwoPunctures.h"
-#include <mkl_cblas.h>
+#include <cblas.h>
 
 TwoPunctures::TwoPunctures(double mp, double mm, double b,
                            double P_plusx, double P_plusy, double P_plusz,