Sema: improved C pointers and casting

 * C pointer types always have allowzero set to true but they omit the
   word allowzero when printed.
 * Implement coercion from C pointers to other pointers.
 * Implement in-memory coercion for slices and pointer-like optionals.
 * Make slicing a C pointer drop the allowzero bit.
 * Value representation for pointer-like optionals is now allowed to use
   pointer tag values in addition to the `opt_payload` tag.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/value.zig b/src/value.zig
index 19c2a73666..382aeeedf7 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -1819,7 +1819,8 @@ pub const Value = extern union {
             .unreachable_value => unreachable,
             .inferred_alloc => unreachable,
             .inferred_alloc_comptime => unreachable,
-            else => unreachable,
+
+            else => false,
         };
     }