[Fix] (ShaderTranspiler, DirectVulkan, MG_IntegrationTest): patch both of iterationRP's under-declared subgroup scratch arrays

The previous commit's fingerprint was pinned to one array's incidental
dimensions - workgroup exactly 32x16x1, element exactly vec2, length
exactly 32 - which is the auto-exposure reduction and nothing else. The
pack ships the same idiom twice:

  - auto-exposure:  32x16 (512 invocations), shared vec2 prefixSumCache[32]
  - RTW warp:       1024 invocations,        shared float prefixSumCache[64]

so the warp kept writing 128 subgroups into 64 entries on an 8-lane
device and the retrace stayed bit-identically wrong (ssim 0.027902).

Key the fingerprint on the pack's idiom instead of one array's shape: a
workgroup array of 32-bit floats indexed by gl_SubgroupID, fed by a
subgroup scan, whose declared length is below ceil(invocations / native
width). Three properties keep that a targeted repair rather than a
general array resizer:

  - the index must BE gl_SubgroupID (through OpCopyObject, a signedness
    OpBitcast, or a spill whose every store is that id), so an index
    masked or clamped into range is left alone;
  - the >= 16-lane early-out is retained, so every module on the devices
    the pack was written for passes through byte-identical;
  - growth is certified against maxComputeSharedMemorySize using a
    natural-alignment layout model, and declined outright when a
    declaration cannot be sized, so a patched module can never fail
    pipeline creation where the original would not have.

Verified against the shaders the CI trace actually contains: of the 14
compute modules in the fixture exactly these two change, the other
twelve are byte-identical, and all fourteen pass spirv-val. The
integration scenario grows a second case for the 1024-invocation shape;
both abort with heap corruption when the patch is disabled.

MobileGL/MG_Util/ShaderTranspiler/ShaderCompiler.cpp

@@ -912,12 +912,13 @@ namespace MobileGL {
 
             bool ShaderCompiler::FixIterationRPSubgroupScratchForVulkan(
                 const Vector<Uint32>& inputBinary, Vector<uint32_t>& outputBinary,
-                const Uint32 nativeSubgroupSize, const bool enableSpirvValidation) {
+                const Uint32 nativeSubgroupSize, const Uint32 maxWorkgroupScratchBytes,
+                const bool enableSpirvValidation) {
                 using namespace spvtools;
                 Optimizer optimizer(SPV_ENV_VULKAN_1_1);
                 optimizer.RegisterPass(
                     FixIterationRPSubgroupScratchPass::CreateFixIterationRPSubgroupScratchPass(
-                        nativeSubgroupSize));
+                        nativeSubgroupSize, maxWorkgroupScratchBytes));
 
                 return RunOptimizerChecked("FixIterationRPSubgroupScratchForVulkan", optimizer,
                                            inputBinary, outputBinary, true, enableSpirvValidation);