sysAlloc to avoid fragmentation. However, there is no way to free
  persistentalloced objects (hence the name).

* fixalloc is a SLAB-style allocator that allocates objects of a fixed
  size. fixalloced objects can be freed, but this memory can only be
  reused by the same fixalloc pool, so it can only be reused for
  objects of the same type.

In general, types that are allocated using any of these should be

	}

	spanalloc              fixalloc // allocator for span*
	cachealloc             fixalloc // allocator for mcache*
	specialfinalizeralloc  fixalloc // allocator for specialfinalizer*
	specialprofilealloc    fixalloc // allocator for specialprofile*
	specialReachableAlloc  fixalloc // allocator for specialReachable
	specialPinCounterAlloc fixalloc // allocator for specialPinCounter

	// maxAlloc is the maximum size of an allocation. On 64-bit,
	// it's theoretically possible to allocate 1<<heapAddrBits bytes. On
	// 32-bit, however, this is one less than 1<<32 because the
	// number of bytes in the address space doesn't actually fit
	// in a uintptr.
	maxAlloc = (1 << heapAddrBits) - (1-_64bit)*1

		capmem = roundupsize(uintptr(newcap), noscan)
		overflow = uintptr(newcap) > maxAlloc
		newcap = int(capmem)
	case et.Size_ == goarch.PtrSize:
		lenmem = uintptr(oldLen) * goarch.PtrSize
		newlenmem = uintptr(newLen) * goarch.PtrSize
		capmem = roundupsize(uintptr(newcap)*goarch.PtrSize, noscan)
		overflow = uintptr(newcap) > maxAlloc/goarch.PtrSize
		newcap = int(capmem / goarch.PtrSize)
	case isPowerOfTwo(et.Size_):

	*(*slice)(unsafe.Pointer(&b)) = slice{p, size, int(cap)}
	return
}

// rawruneslice allocates a new rune slice. The rune slice is not zeroed.
func rawruneslice(size int) (b []rune) {
	if uintptr(size) > maxAlloc/4 {
		throw("out of memory")
	}
	mem := roundupsize(uintptr(size)*4, true)
	p := mallocgc(mem, nil, false)
	if mem != uintptr(size)*4 {
		memclrNoHeapPointers(add(p, uintptr(size)*4), mem-uintptr(size)*4)
	}

	// If we are running on the system stack then dst might be an
	// address on the stack, which is OK.
	gp := getg()
	if gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}

	// Allocating memory can write to various mfixalloc structs
	// that look like they are non-Go memory.
	if gp.m.mallocing != 0 {
		return
	}

	// If the object is pinned, it's safe to store it in C memory. The GC
	// ensures it will not be moved or freed.

    kFree = 1,
    kRead = 2,
    kWrite = 3
  };

 public:
  bool IsAlloc() const { return effects_.test(kAlloc); }
  bool IsFree() const { return effects_.test(kFree); }
  bool IsRead() const { return effects_.test(kRead); }
  bool IsWrite() const { return effects_.test(kWrite); }
  bool IsAllocOnly() const { return IsAlloc() && effects_.count() == 1; }
  bool IsReadOnly() const { return IsRead() && effects_.count() == 1; }

	Type   *types.Type // type signature of the function.
	Blocks []*Block    // unordered set of all basic blocks (note: not indexable by ID)
	Entry  *Block      // the entry basic block

	bid idAlloc // block ID allocator
	vid idAlloc // value ID allocator

	HTMLWriter     *HTMLWriter    // html writer, for debugging

#include <linux/capability.h>
#include <linux/cryptouser.h>
#include <linux/devlink.h>
#include <linux/dm-ioctl.h>
#include <linux/errqueue.h>
#include <linux/ethtool_netlink.h>
#include <linux/falloc.h>
#include <linux/fanotify.h>
#include <linux/fib_rules.h>
#include <linux/filter.h>
#include <linux/fs.h>
#include <linux/fscrypt.h>
#include <linux/fsverity.h>
#include <linux/genetlink.h>

	}
	if hchanSize%maxAlign != 0 || elem.Align_ > maxAlign {
		throw("makechan: bad alignment")
	}

	mem, overflow := math.MulUintptr(elem.Size_, uintptr(size))
	if overflow || mem > maxAlloc-hchanSize || size < 0 {
		panic(plainError("makechan: size out of range"))
	}

	// Hchan does not contain pointers interesting for GC when elements stored in buf do not contain pointers.