stage2: progress towards stage3

 * The `@bitCast` workaround is removed in favor of `@ptrCast` properly
   doing element casting for slice element types. This required an
   enhancement both to stage1 and stage2.
 * stage1 incorrectly accepts `.{}` instead of `{}`. stage2 code that
   abused this is fixed.
 * Make some parameters comptime to support functions in switch
   expressions (as opposed to making them function pointers).
 * Avoid relying on local temporaries being mutable.
 * Workarounds for when stage1 and stage2 disagree on function pointer
   types.
 * Workaround recursive formatting bug with a `@panic("TODO")`.
 * Remove unreachable `else` prongs for some inferred error sets.

All in effort towards #89.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/AstGen.zig b/src/AstGen.zig
index 75882c761b..ccce4b0bc8 100644
--- a/src/AstGen.zig
+++ b/src/AstGen.zig
@@ -85,12 +85,12 @@ fn reserveExtra(astgen: *AstGen, size: usize) Allocator.Error!u32 {
 }
 
 fn appendRefs(astgen: *AstGen, refs: []const Zir.Inst.Ref) !void {
-    const coerced = @bitCast([]const u32, refs);
+    const coerced = @ptrCast([]const u32, refs);
     return astgen.extra.appendSlice(astgen.gpa, coerced);
 }
 
 fn appendRefsAssumeCapacity(astgen: *AstGen, refs: []const Zir.Inst.Ref) void {
-    const coerced = @bitCast([]const u32, refs);
+    const coerced = @ptrCast([]const u32, refs);
     astgen.extra.appendSliceAssumeCapacity(coerced);
 }