Gamealloc, Graph, and Graphalloc retail OK (#1675)

* Gamealloc OK

* Graph + Graphalloc OK

* PR review

* gfxalloc

* new lines

* Remove imposter

src/code/gfxalloc.c

@@ -0,0 +1,25 @@
+#include "global.h"
+
+Gfx* Gfx_Open(Gfx* gfx) {
+    return gfx + 1;
+}
+
+Gfx* Gfx_Close(Gfx* gfx, Gfx* dst) {
+    gSPBranchList(gfx, dst);
+    return dst;
+}
+
+void* Gfx_Alloc(Gfx** gfxP, u32 size) {
+    u8* ptr;
+    Gfx* dst;
+
+    size = ALIGN8(size);
+
+    ptr = (u8*)(*gfxP + 1);
+
+    dst = (Gfx*)(ptr + size);
+    gSPBranchList(*gfxP, dst);
+
+    *gfxP = dst;
+    return ptr;
+}