qmath: add qNextPowerOfTwo(unsigned long) - for size_t

This completes the triad uint/ulong/qulonglong, ensuring that one of
them will be size_t and one of them will be uintptr_t (size_t and
uintptr_t don't have to be the same type). The signeds ensure one of
them will be ptrdiff_t too.

Pick-to: 6.5
Change-Id: I9671dee8ceb64aa9b9cafffd17415a0bfcbd68b7
Reviewed-by: Lars Knoll <lars@knoll.priv.no>

src/corelib/kernel/qmath.h

@@ -370,6 +370,16 @@ constexpr inline quint64 qNextPowerOfTwo(qint64 v)
     return qNextPowerOfTwo(quint64(v));
 }
 
+constexpr inline unsigned long qNextPowerOfTwo(unsigned long v)
+{
+    return qNextPowerOfTwo(QIntegerForSizeof<long>::Unsigned(v));
+}
+
+constexpr inline unsigned long qNextPowerOfTwo(long v)
+{
+    return qNextPowerOfTwo(QIntegerForSizeof<long>::Unsigned(v));
+}
+
 QT_END_NAMESPACE
 
 #endif // QMATH_H

src/corelib/tools/qhash.h

@@ -435,7 +435,7 @@ inline constexpr size_t bucketsForCapacity(size_t requestedCapacity) noexcept
         return SpanConstants::NEntries;
     if (requestedCapacity >= maxNumBuckets())
         return maxNumBuckets();
-    return qNextPowerOfTwo(QIntegerForSize<sizeof(size_t)>::Unsigned(2 * requestedCapacity - 1));
+    return qNextPowerOfTwo(2 * requestedCapacity - 1);
 }
 inline constexpr size_t bucketForHash(size_t nBuckets, size_t hash) noexcept
 {