remove compile error for peer result comptime_int and null

closes #2763

Author: andrewrk

src/ir.cpp

@@ -11438,13 +11438,7 @@ static ZigType *ir_resolve_peer_types(IrAnalyze *ira, AstNode *source_node, ZigT
             }
         }
     } else if (any_are_null && prev_inst->value->type->id != ZigTypeIdNull) {
-        if (prev_inst->value->type->id == ZigTypeIdComptimeInt ||
-            prev_inst->value->type->id == ZigTypeIdComptimeFloat)
-        {
-            ir_add_error_node(ira, source_node,
-                buf_sprintf("unable to make maybe out of number literal"));
-            return ira->codegen->builtin_types.entry_invalid;
-        } else if (prev_inst->value->type->id == ZigTypeIdOptional) {
+        if (prev_inst->value->type->id == ZigTypeIdOptional) {
             return prev_inst->value->type;
         } else {
             if ((err = type_resolve(ira->codegen, prev_inst->value->type, ResolveStatusSizeKnown)))

test/stage1/behavior/cast.zig

@@ -710,3 +710,24 @@ test "return u8 coercing into ?u32 return type" {
     S.doTheTest();
     comptime S.doTheTest();
 }
+
+test "peer result null and comptime_int" {
+    const S = struct {
+        fn blah(n: i32) ?i32 {
+            if (n == 0) {
+                return null;
+            } else if (n < 0) {
+                return -1;
+            } else {
+                return 1;
+            }
+        }
+    };
+
+    expect(S.blah(0) == null);
+    comptime expect(S.blah(0) == null);
+    expect(S.blah(10).? == 1);
+    comptime expect(S.blah(10).? == 1);
+    expect(S.blah(-10).? == -1);
+    comptime expect(S.blah(-10).? == -1);
+}