Add gas test confirming that br instructions do not end blocks.

tests/fixtures/gas/branch.wat

@@ -0,0 +1,27 @@
+(module
+	(func $fibonacci_with_break (result i32)
+		(local $x i32) (local $y i32)
+
+		(block $unrolled_loop
+			(set_local $x (i32.const 0))
+			(set_local $y (i32.const 1))
+
+			get_local $x
+			get_local $y
+			tee_local $x
+			i32.add
+			set_local $y
+
+			i32.const 1
+			br_if $unrolled_loop
+
+			get_local $x
+			get_local $y
+			tee_local $x
+			i32.add
+			set_local $y
+		)
+
+		get_local $y
+	)
+)

tests/fixtures/gas/call.wat

@@ -2,7 +2,6 @@
 	(func $add_locals (param $x i32) (param $y i32) (result i32)
 		(local $t i32)
 
-		;; This looks 
 		get_local $x
 		get_local $y
 		call $add

tests/fixtures/gas/ifs.wat

@@ -1,9 +1,9 @@
 (module
 	(func (param $x i32) (result i32)
 		(if (result i32)
-          	(i32.const 1)
-			(i32.add (get_local $x) (i32.const 1))
-			(i32.popcnt (get_local $x))
+			(i32.const 1)
+			(then (i32.add (get_local $x) (i32.const 1)))
+			(else (i32.popcnt (get_local $x)))
 		)
 	)
 )

tests/fixtures/gas/simple.wat

@@ -1,9 +1,11 @@
 (module
 	(func (export "simple")
 		(if (i32.const 1)
-			(loop
-				i32.const 123
-				drop
+			(then
+				(loop
+					i32.const 123
+					drop
+				)
 			)
 		)
 	)