Translate bootstrapping main from C to LLVM IR

This avoids needing a C compiler for every platform.

src/runtime/runtime.c

@@ -1,21 +0,0 @@
-
-#include "runtime.h"
-#include <string.h>
-
-void go_init() __asm__("runtime.initAll");
-void go_main() __asm__("main.main");
-
-int main() {
-	go_init();
-	go_main();
-
-	return 0;
-}
-
-__attribute__((weak))
-void * memset(void *s, int c, size_t n) {
-	for (size_t i = 0; i < n; i++) {
-		((uint8_t*)s)[i] = c;
-	}
-	return s;
-}

src/runtime/runtime.ll

@@ -0,0 +1,10 @@
+source_filename = "runtime/runtime.ll"
+
+declare void @runtime.initAll()
+declare void @main.main()
+
+define i32 @main() {
+	call void @runtime.initAll()
+	call void @main.main()
+	ret i32 0
+}