More GCC compatibility/warning fixes (#3118)

* Wrap >4-char literals in a MULTI_CHAR macro

Modern compilers do not support CW's non-standard behavior with
>4 char literals. We can, however, use a constexpr function to
compute the u64 values directly. This leaves <=4 char literals
unchanged.

* Replace non-pointer usages of NULL with 0

* Define NULL to nullptr on C++11 and above

* Fix more -Wpointer-arith and -Woverflow warnings

* Replace u32/s32 with uintptr_t/intptr_t where appropriate

* JSUOutputStream: Overload all standard int types

1 files changed, 1 insertions, 1 deletions

diff --git a/src/JSystem/JAudio2/JASSimpleWaveBank.cpp b/src/JSystem/JAudio2/JASSimpleWaveBank.cpp
index 9bc0bbf31d..c599a0e857 100644
--- a/src/JSystem/JAudio2/JASSimpleWaveBank.cpp
+++ b/src/JSystem/JAudio2/JASSimpleWaveBank.cpp
@@ -42,7 +42,7 @@ JASWaveArc* JASSimpleWaveBank::getWaveArc(u32 no) {
 int JASSimpleWaveBank::TWaveHandle::getWavePtr() const {
     void* base = mHeap->getBase();
     if (base == NULL) {
-        return NULL;
+        return 0;
     }
     return (intptr_t)base + mWaveInfo.field_0x08;
 }