Restart LLVM IR SSA generation

This is the third go and I'm going for it!

examples/test.ll

@@ -0,0 +1,16 @@
+define void @main() {
+entry:
+	%0 = alloca i64, align 8
+	store i64 zeroinitializer, i64* %0
+	store i64 137, i64* %0
+	%1 = load i64, i64* %0
+	add i64 1, %1
+	store i64 %2, i64* %0
+	%3 = alloca float, align 4
+	store float zeroinitializer, float* %3
+	store float 0x3f8147ae00000000, float* %3
+	%4 = load float, float* %3
+	fadd float %4, 0x3f7d70a400000000
+	store float %5, float* %3
+	ret void
+}