Sema: fix analyzeBlockBody logic

Previously, when a coercion needed to be inserted into a break
instruction, the `br` AIR instruction would be rewritten so that the
block operand was a sub-block that did the coercion. The problem is that
the sub-block itself was never added to the parent block, resulting in
the `br` instruction operand being a bad reference.

Now, the `br` AIR instruction that needs to have coercion instructions
added is replaced with the sub-block itself with type `noreturn`, and
then the sub-block has the coercion instructions and a new `br`
instruction that breaks from the original block.

LLVM backend needed to be fixed to lower `noreturn` blocks without
emitting an unused LLVM basic block.

1 files changed, 6 insertions, 6 deletions

diff --git a/test/behavior.zig b/test/behavior.zig
index c6d090b28a..2da66e841b 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -24,25 +24,25 @@ test {
     _ = @import("behavior/defer.zig");
     _ = @import("behavior/enum.zig");
     _ = @import("behavior/error.zig");
+    _ = @import("behavior/error.zig");
+    _ = @import("behavior/generics.zig");
     _ = @import("behavior/hasdecl.zig");
     _ = @import("behavior/hasfield.zig");
     _ = @import("behavior/if.zig");
     _ = @import("behavior/int128.zig");
+    _ = @import("behavior/member_func.zig");
     _ = @import("behavior/null.zig");
+    _ = @import("behavior/optional.zig");
     _ = @import("behavior/pointers.zig");
     _ = @import("behavior/ptrcast.zig");
     _ = @import("behavior/pub_enum.zig");
     _ = @import("behavior/struct.zig");
+    _ = @import("behavior/this.zig");
+    _ = @import("behavior/translate_c_macros.zig");
     _ = @import("behavior/truncate.zig");
     _ = @import("behavior/underscore.zig");
     _ = @import("behavior/usingnamespace.zig");
     _ = @import("behavior/while.zig");
-    _ = @import("behavior/this.zig");
-    _ = @import("behavior/member_func.zig");
-    _ = @import("behavior/translate_c_macros.zig");
-    _ = @import("behavior/generics.zig");
-    _ = @import("behavior/error.zig");
-    _ = @import("behavior/optional.zig");
 
     if (builtin.object_format != .c) {
         // Tests that pass for stage1 and stage2 but not the C backend.