DetermineCompiler: Relax _CMAKE_TOOLCHAIN_PREFIX detection

Now detect _CMAKE_TOOLCHAIN_PREFIX whenever a compilers
name matches the heuristics, instead of only doing it
when cross compiling

Modules/CMakeDetermineCCompiler.cmake

@@ -153,7 +153,7 @@ endif ()
 # NAME_WE cannot be used since then this test will fail for names like
 # "arm-unknown-nto-qnx6.3.0-gcc.exe", where BASENAME would be
 # "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
-if (CMAKE_CROSSCOMPILING  AND NOT _CMAKE_TOOLCHAIN_PREFIX)
+if (NOT _CMAKE_TOOLCHAIN_PREFIX)
 
   if(CMAKE_C_COMPILER_ID MATCHES "GNU|Clang|QCC")
     get_filename_component(COMPILER_BASENAME "${CMAKE_C_COMPILER}" NAME)

Modules/CMakeDetermineCXXCompiler.cmake

@@ -150,7 +150,7 @@ endif ()
 # "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
 
 
-if (CMAKE_CROSSCOMPILING  AND NOT  _CMAKE_TOOLCHAIN_PREFIX)
+if (NOT _CMAKE_TOOLCHAIN_PREFIX)
 
   if("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU|Clang|QCC")
     get_filename_component(COMPILER_BASENAME "${CMAKE_CXX_COMPILER}" NAME)

Modules/CMakeDetermineFortranCompiler.cmake

@@ -249,7 +249,7 @@ endif ()
 # NAME_WE cannot be used since then this test will fail for names like
 # "arm-unknown-nto-qnx6.3.0-gcc.exe", where BASENAME would be
 # "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
-if (CMAKE_CROSSCOMPILING  AND NOT _CMAKE_TOOLCHAIN_PREFIX)
+if (NOT _CMAKE_TOOLCHAIN_PREFIX)
 
   if(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
     get_filename_component(COMPILER_BASENAME "${CMAKE_Fortran_COMPILER}" NAME)

Modules/CMakeDetermineOBJCXXCompiler.cmake

@@ -145,7 +145,7 @@ endif ()
 # "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
 
 
-if (CMAKE_CROSSCOMPILING  AND NOT  _CMAKE_TOOLCHAIN_PREFIX)
+if (NOT _CMAKE_TOOLCHAIN_PREFIX)
 
   if("${CMAKE_OBJCXX_COMPILER_ID}" MATCHES "GNU|Clang|QCC")
     get_filename_component(COMPILER_BASENAME "${CMAKE_OBJCXX_COMPILER}" NAME)