Fix AVR target to define ints properly (#12817)

* Fix AVR target to define ints properly

* Fix more than AVR target

* Test to see how robust not using stdint is

* Fix for namespaces using cstdint

* Fix for pre C++11 compilers when using namespaces

lib/nimbase.h

@@ -17,6 +17,7 @@ __DMC__
 __POCC__
 __TINYC__
 __clang__
+__AVR__
 */
 
 
@@ -258,16 +259,28 @@ __clang__
 #include <stddef.h>
 
 /* C99 compiler? */
-#if (defined(__STD_VERSION__) && (__STD_VERSION__ >= 199901))
+#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901))
 #  define HAVE_STDINT_H
 #endif
 
-#if defined(__LCC__) || defined(__DMC__) || defined(__POCC__)
+/* Known compiler with stdint.h that doesn't fit the general pattern? */
+#if defined(__LCC__) || defined(__DMC__) || defined(__POCC__) || \
+  defined(__AVR__) || (defined(__cplusplus) && (__cplusplus < 201103))
 #  define HAVE_STDINT_H
 #endif
 
+#if (!defined(HAVE_STDINT_H) && defined(__cplusplus) && (__cplusplus >= 201103))
+#  define HAVE_CSTDINT
+#endif
+
+
 /* wrap all Nim typedefs into namespace Nim */
 #ifdef USE_NIM_NAMESPACE
+#ifdef HAVE_CSTDINT
+#include <cstdint>
+#else
+#include <stdint.h>
+#endif
 namespace USE_NIM_NAMESPACE {
 #endif
 
@@ -308,33 +321,80 @@ namespace USE_NIM_NAMESPACE {
 typedef signed char NI8;
 typedef signed short int NI16;
 typedef signed int NI32;
+typedef __int64 NI64;
 /* XXX: Float128? */
 typedef unsigned char NU8;
 typedef unsigned short int NU16;
-typedef unsigned __int64 NU64;
-typedef __int64 NI64;
 typedef unsigned int NU32;
+typedef unsigned __int64 NU64;
 #elif defined(HAVE_STDINT_H)
+#ifndef USE_NIM_NAMESPACE
 #  include <stdint.h>
+#endif
 typedef int8_t NI8;
 typedef int16_t NI16;
 typedef int32_t NI32;
 typedef int64_t NI64;
-typedef uint64_t NU64;
 typedef uint8_t NU8;
 typedef uint16_t NU16;
 typedef uint32_t NU32;
+typedef uint64_t NU64;
+#elif defined(HAVE_CSTDINT)
+#ifndef USE_NIM_NAMESPACE
+#  include <cstdint>
+#endif
+typedef std::int8_t NI8;
+typedef std::int16_t NI16;
+typedef std::int32_t NI32;
+typedef std::int64_t NI64;
+typedef std::uint8_t NU8;
+typedef std::uint16_t NU16;
+typedef std::uint32_t NU32;
+typedef std::uint64_t NU64;
+#else
+/* Unknown compiler/version, do our best */
+#ifdef __INT8_TYPE__
+typedef __INT8_TYPE__ NI8;
 #else
 typedef signed char NI8;
+#endif
+#ifdef __INT16_TYPE__
+typedef __INT16_TYPE__ NI16;
+#else
 typedef signed short int NI16;
+#endif
+#ifdef __INT32_TYPE__
+typedef __INT32_TYPE__ NI32;
+#else
 typedef signed int NI32;
+#endif
+#ifdef __INT64_TYPE__
+typedef __INT64_TYPE__ NI64;
+#else
+typedef long long int NI64;
+#endif
 /* XXX: Float128? */
+#ifdef __UINT8_TYPE__
+typedef __UINT8_TYPE__ NU8;
+#else
 typedef unsigned char NU8;
+#endif
+#ifdef __UINT16_TYPE__
+typedef __UINT16_TYPE__ NU16;
+#else
 typedef unsigned short int NU16;
-typedef unsigned long long int NU64;
-typedef long long int NI64;
+#endif
+#ifdef __UINT32_TYPE__
+typedef __UINT32_TYPE__ NU32;
+#else
 typedef unsigned int NU32;
 #endif
+#ifdef __UINT64_TYPE__
+typedef __UINT64_TYPE__ NU64;
+#else
+typedef unsigned long long int NU64;
+#endif
+#endif
 
 #ifdef NIM_INTBITS
 #  if NIM_INTBITS == 64