Match stack_pointer with C code (#530)

* Remove useless comment

* Small amounts of documenting, official names, and use some new knowledge to match what was previously thought to be only possible with hasm.

* Define the proper type for the stack_pointer function, and come up with a solution for GCC builds that should hopefully work.

* Partial revert to support getting the actual stack pointer for GCC builds

* Come up with a better GCC build option for getting the stack pointer

* Update the score

src/get_stack_pointer.c

@@ -0,0 +1,21 @@
+#include "memory.h"
+
+#ifdef __sgi
+/**
+ * Uses IDO specific -dollar compiler flag to get the current stack pointer.
+ * Official Name: diCpuTraceCurrentStack
+ */
+StackInfo *stack_pointer(void) {
+    return (StackInfo *) __$sp;
+}
+#else
+/**
+ * Uses GCC specific code to get the current stack pointer.
+ * Official Name: diCpuTraceCurrentStack
+ */
+StackInfo *stack_pointer(void) {
+    register StackInfo *sp;
+    asm volatile ("move %0, $sp\n": "=r"(sp));
+    return sp;
+}
+#endif