Value: handle runtime_int in hashPtr

Closes #12702

src/value.zig

@@ -2555,6 +2555,9 @@ pub const Value = extern union {
             .lazy_size,
             => return hashInt(ptr_val, hasher, target),
 
+            // The value is runtime-known and shouldn't affect the hash.
+            .runtime_int => {},
+
             else => unreachable,
         }
     }

test/behavior/src.zig

@@ -20,3 +20,14 @@ test "@src" {
 
     try doTheTest();
 }
+
+test "@src used as a comptime parameter" {
+    const S = struct {
+        fn Foo(comptime _: std.builtin.SourceLocation) type {
+            return struct {};
+        }
+    };
+    const T1 = S.Foo(@src());
+    const T2 = S.Foo(@src());
+    try expect(T1 != T2);
+}