Fortran: Detect PGI compiler version

Port logic from the "Compiler/PGI-DetermineCompiler" module into
"CMakeFortranCompilerId.F.in".

Modules/CMakeFortranCompilerId.F.in

@@ -79,6 +79,11 @@
 # endif
 #elif defined(__PGI)
         PRINT *, 'INFO:compiler[PGI]'
+# define COMPILER_VERSION_MAJOR DEC(__PGIC__)
+# define COMPILER_VERSION_MINOR DEC(__PGIC_MINOR__)
+# if defined(__PGIC_PATCHLEVEL__)
+#  define COMPILER_VERSION_PATCH DEC(__PGIC_PATCHLEVEL__)
+# endif
 #elif defined(_SGI_COMPILER_VERSION) || defined(_COMPILER_VERSION)
         PRINT *, 'INFO:compiler[MIPSpro]'
 #       if 0