Fix windows icb macros (#416)

* Distinct new intel llvm compiler on windows

intel llvm compiler uses clang-cl who also defines _MSC_VER, which let icx find msc complex.h instead intel copmlex.h

* Undef I in windows complex.h

I macro is defined by windows complex.h which is used as variable name in arpackSolver as well.

CHANGES

@@ -1,5 +1,9 @@
 arpack-ng - 3.9.1
 
+[ Ruoyu Feng ]
+ * ICB(arpackdef.h): distinct intel llvm compiler (icx with clang-cl) from msvc on windows
+ * ICB(arpackdef.h): Undef macro I if complex.h from msvc version is loaded, which is an usual name and causes issues on arpackSolver.
+
 [ Fabien Péan ]
  * README: Add details on Windows installation.
 

arpackdef.h.in

@@ -13,10 +13,11 @@
 #define a_int int
 #define a_uint unsigned int
 #endif
-#ifdef _MSC_VER
+#if !defined(__INTEL_LLVM_COMPILER) && defined(_MSC_VER)
 #ifndef _CRT_USE_C_COMPLEX_H
 #define _CRT_USE_C_COMPLEX_H
 #include <complex.h>
+#undef I
 #undef _CRT_USE_C_COMPLEX_H
 #else
 #include <complex.h>