mem: implement most of StandardAllocator (#860)

This was tested using `https://github.com/node-dot-cpp/alloc-test` plus a few other by-hand tests.

It seems to work for the case we care about (sysmodules without thread cache-ing).

External users are advised to build with assertions on and contact SciresM if you find issues.

This is a lot of code to have gotten right in one go, and it was written mostly after midnight while sick, so there are probably un-noticed issues.

libraries/libvapours/include/vapours/svc/svc_types_common.hpp

@@ -60,6 +60,8 @@ namespace ams::svc {
             T pointer;
         public:
             constexpr ALWAYS_INLINE UserPointer(T p) : pointer(p) { /* ... */ }
+
+            constexpr ALWAYS_INLINE T GetPointerUnsafe() { return this->pointer; }
     };
 
     template<typename T>
@@ -168,11 +170,11 @@ namespace ams::svc {
         InitialProcessIdRangeInfo_Maximum = 1,
     };
 
-    enum PhysicalMemoryInfo : u64 {
-        PhysicalMemoryInfo_Application  = 0,
-        PhysicalMemoryInfo_Applet       = 1,
-        PhysicalMemoryInfo_System       = 2,
-        PhysicalMemoryInfo_SystemUnsafe = 3,
+    enum PhysicalMemorySystemInfo : u64 {
+        PhysicalMemorySystemInfo_Application  = 0,
+        PhysicalMemorySystemInfo_Applet       = 1,
+        PhysicalMemorySystemInfo_System       = 2,
+        PhysicalMemorySystemInfo_SystemUnsafe = 3,
     };
 
     enum LastThreadInfoFlag : u32 {