Add support for Cray, Fujitsu, and Intel ICX compilers

The following preprocessor macros are added:

- EIGEN_COMP_CPE and EIGEN_COMP_CLANGCPE version number of the CRAY compiler if
  Eigen is compiled with the Cray C++ compiler, 0 otherwise.

- EIGEN_COMP_FCC and EIGEN_COMP_CLANGFCC version number of the FCC compiler if
  Eigen is compiled with the Fujitsu C++ compiler, 0 otherwise

- EIGEN_COMP_CLANGICC version number of the ICX compiler if Eigen is compiled
  with the Intel oneAPI C++ compiler, 0 otherwise

All three compilers (Cray, Fujitsu, Intel) offer a traditional and a Clang-based
frontend. This is distinguished by the CLANG prefix.

Eigen/src/Core/arch/NEON/Complex.h

@@ -376,7 +376,7 @@ template<> EIGEN_STRONG_INLINE Packet2cf psqrt<Packet2cf>(const Packet2cf& a) {
 #if EIGEN_ARCH_ARM64 && !EIGEN_APPLE_DOUBLE_NEON_BUG
 
 // See bug 1325, clang fails to call vld1q_u64.
-#if EIGEN_COMP_CLANG || EIGEN_COMP_CASTXML
+#if EIGEN_COMP_CLANG || EIGEN_COMP_CASTXML || EIGEN_COMP_CPE
   static uint64x2_t p2ul_CONJ_XOR = {0x0, 0x8000000000000000};
 #else
   const uint64_t  p2ul_conj_XOR_DATA[] = { 0x0, 0x8000000000000000 };

Eigen/src/Core/util/DisableStupidWarnings.h

@@ -54,7 +54,7 @@
     #pragma clang diagnostic ignored "-Wc11-extensions"
   #endif
 
-#elif defined __GNUC__
+#elif defined __GNUC__ && !defined(__FUJITSU)
 
   #if (!defined(EIGEN_PERMANENTLY_DISABLE_STUPID_WARNINGS)) &&  (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
     #pragma GCC diagnostic push

Eigen/src/Core/util/Macros.h

@@ -87,13 +87,20 @@
   #define EIGEN_COMP_LLVM 0
 #endif
 
-/// \internal EIGEN_COMP_ICC set to __INTEL_COMPILER if the compiler is Intel compiler, 0 otherwise
+/// \internal EIGEN_COMP_ICC set to __INTEL_COMPILER if the compiler is Intel icc compiler, 0 otherwise
 #if defined(__INTEL_COMPILER)
   #define EIGEN_COMP_ICC __INTEL_COMPILER
 #else
   #define EIGEN_COMP_ICC 0
 #endif
 
+/// \internal EIGEN_COMP_CLANGICC set to __INTEL_CLANG_COMPILER if the compiler is Intel icx compiler, 0 otherwise
+#if defined(__INTEL_CLANG_COMPILER)
+  #define EIGEN_COMP_CLANGICC __INTEL_CLANG_COMPILER
+#else
+  #define EIGEN_COMP_CLANGICC 0
+#endif
+
 /// \internal EIGEN_COMP_MINGW set to 1 if the compiler is mingw
 #if defined(__MINGW32__)
   #define EIGEN_COMP_MINGW 1
@@ -193,9 +200,45 @@
   #define EIGEN_COMP_EMSCRIPTEN 0
 #endif
 
+/// \internal EIGEN_COMP_FCC set to FCC version if the compiler is Fujitsu Compiler (traditional mode)
+/// \note The Fujitsu C/C++ compiler uses the traditional mode based
+/// on EDG g++ 6.1 by default or if envoked with the -Nnoclang flag
+#if defined(__FUJITSU)
+  #define EIGEN_COMP_FCC (__FCC_major__*100+__FCC_minor__*10+__FCC_patchlevel__)
+#else
+  #define EIGEN_COMP_FCC 0
+#endif
+
+/// \internal EIGEN_COMP_CLANGFCC set to FCC version if the compiler is Fujitsu Compiler (Clang mode)
+/// \note The Fujitsu C/C++ compiler uses the non-traditional mode
+/// based on Clang 7.1.0 if envoked with the -Nclang flag
+#if defined(__CLANG_FUJITSU)
+  #define EIGEN_COMP_CLANGFCC (__FCC_major__*100+__FCC_minor__*10+__FCC_patchlevel__)
+#else
+  #define EIGEN_COMP_CLANGFCC 0
+#endif
+
+/// \internal EIGEN_COMP_CPE set to CPE version if the compiler is HPE Cray Compiler (GCC based)
+/// \note This is the SVE-enabled C/C++ compiler from the HPE Cray
+/// Programming Environment (CPE) based on Cray GCC 8.1
+#if defined(_CRAYC) && !defined(__clang__)
+  #define EIGEN_COMP_CPE (_RELEASE_MAJOR*100+_RELEASE_MINOR*10+_RELEASE_PATCHLEVEL)
+#else
+  #define EIGEN_COMP_CPE 0
+#endif
+
+/// \internal EIGEN_COMP_CLANGCPE set to CPE version if the compiler is HPE Cray Compiler (Clang based)
+/// \note This is the C/C++ compiler from the HPE Cray Programming
+/// Environment (CPE) based on Cray Clang 11.0 without SVE-support
+#if defined(_CRAYC) && defined(__clang__)
+  #define EIGEN_COMP_CLANGCPE (_RELEASE_MAJOR*100+_RELEASE_MINOR*10+_RELEASE_PATCHLEVEL)
+#else
+  #define EIGEN_COMP_CLANGCPE 0
+#endif
+
 
 /// \internal EIGEN_GNUC_STRICT set to 1 if the compiler is really GCC and not a compatible compiler (e.g., ICC, clang, mingw, etc.)
-#if EIGEN_COMP_GNUC && !(EIGEN_COMP_CLANG || EIGEN_COMP_ICC || EIGEN_COMP_MINGW || EIGEN_COMP_PGI || EIGEN_COMP_IBM || EIGEN_COMP_ARM || EIGEN_COMP_EMSCRIPTEN)
+#if EIGEN_COMP_GNUC && !(EIGEN_COMP_CLANG || EIGEN_COMP_ICC || EIGEN_COMP_CLANGICC || EIGEN_COMP_MINGW || EIGEN_COMP_PGI || EIGEN_COMP_IBM || EIGEN_COMP_ARM || EIGEN_COMP_EMSCRIPTEN || EIGEN_COMP_FCC || EIGEN_COMP_CLANGFCC || EIGEN_COMP_CPE || EIGEN_COMP_CLANGCPE)
   #define EIGEN_COMP_GNUC_STRICT 1
 #else
   #define EIGEN_COMP_GNUC_STRICT 0

Eigen/src/Core/util/ReenableStupidWarnings.h

@@ -12,7 +12,7 @@
     #pragma warning pop
   #elif defined __clang__
     #pragma clang diagnostic pop
-  #elif defined __GNUC__  &&  (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
+  #elif defined __GNUC__  &&  !defined(__FUJITSU) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
     #pragma GCC diagnostic pop
   #endif