;; Ensure that `do`-`while`-style loops, with conditional backedges, are properly
;; supported, via `break if` (as `continuing { ... if c { break; } }` is illegal).
;;
;; The SPIR-V below was compiled from this GLSL fragment shader:
;; ```glsl
;; #version 450
;;
;; void f(bool cond) {
;;     do {} while(cond);
;; }
;;
;; void main() {
;;     f(false);
;; }
;; ```

               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %main "main"
               OpExecutionMode %main OriginUpperLeft
               OpSource GLSL 450
               OpName %main "main"
               OpName %f_b1_ "f(b1;"
               OpName %cond "cond"
               OpName %param "param"
       %void = OpTypeVoid
          %3 = OpTypeFunction %void
       %bool = OpTypeBool
%_ptr_Function_bool = OpTypePointer Function %bool
          %8 = OpTypeFunction %void %_ptr_Function_bool
      %false = OpConstantFalse %bool

       %main = OpFunction %void None %3
          %5 = OpLabel
      %param = OpVariable %_ptr_Function_bool Function
               OpStore %param %false
         %19 = OpFunctionCall %void %f_b1_ %param
               OpReturn
               OpFunctionEnd

      %f_b1_ = OpFunction %void None %8
       %cond = OpFunctionParameter %_ptr_Function_bool

         %11 = OpLabel
               OpBranch %12

         %12 = OpLabel
               OpLoopMerge %14 %15 None
               OpBranch %13

         %13 = OpLabel
               OpBranch %15

;; This is the "continuing" block, and it contains a conditional branch between
;; the backedge (back to the loop header) and the loop merge ("break") target.
         %15 = OpLabel
         %16 = OpLoad %bool %cond
               OpBranchConditional %16 %12 %14

         %14 = OpLabel
               OpReturn

               OpFunctionEnd