[scudo] Use stdint types for internal scudo types

[cryptoad]

Summary

scudo::uptr was defined as an unsigned long on 32-b platform,
while a uintptr_t is usually defined as an unsigned int.
This worked, this was not consistent, particularly with regard to
format string specifiers.

As suggested by Vitaly, since we are including stdint.h, define
the internal scudo integer types to those.

[hctim]

Side note - it'd be nice at some point if we can LSC all the use-of-custom-types away, any reason to keep them?

[cryptoad]

In D108089#2947081, @hctim wrote:

Side note - it'd be nice at some point if we can LSC all the use-of-custom-types away, any reason to keep them?

Yeah I guess they probably should go away at some point.
There was the advantage that they are shorter to type and that they can be redefined to something different per platform/whatever, but we are converging towards stdint types now.

compiler-rt/lib/scudo/standalone/internal_defs.h

#define SCUDO_REQUIRE_CONSTANT_INITIALIZATION                                  \
   __attribute__((__require_constant_initialization__))
 #else
 #define SCUDO_REQUIRE_CONSTANT_INITIALIZATION
 #endif
 #endif
 
 namespace scudo {
 
-typedef unsigned long uptr;
-typedef unsigned char u8;
-typedef unsigned short u16;
-typedef unsigned int u32;
-typedef unsigned long long u64;
-typedef signed long sptr;
-typedef signed char s8;
-typedef signed short s16;
-typedef signed int s32;
-typedef signed long long s64;
+typedef uintptr_t uptr;
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef intptr_t sptr;
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
 
 // The following two functions have platform specific implementations.
 void outputRaw(const char *Buffer);
 void NORETURN die();
 
 #define RAW_CHECK_MSG(Expr, Msg)                                               \
   do {                                                                         \
     if (UNLIKELY(!(Expr))) {                                                   \