[spirv] Dump spirv.module for Metal and WebGPU targets (#14066)

When given `--iree-hal-dump-executable-intermediates-to=`,
to be consistent with Vulkan side:
https://github.com/openxla/iree/pull/14058.

compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV/MetalSPIRVTarget.cpp

diff --git a/compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV/MetalSPIRVTarget.cpp b/compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV/MetalSPIRVTarget.cpp
index 6ec44ae..f62d15c 100644
--- a/compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV/MetalSPIRVTarget.cpp
+++ b/compiler/src/iree/compiler/Dialect/HAL/Target/MetalSPIRV/MetalSPIRVTarget.cpp
@@ -124,6 +124,13 @@
                                     OpBuilder &executableBuilder) override {
     ModuleOp innerModuleOp = variantOp.getInnerModule();
     auto spvModuleOp = *innerModuleOp.getOps<spirv::ModuleOp>().begin();
+    if (!options.dumpIntermediatesPath.empty()) {
+      std::string assembly;
+      llvm::raw_string_ostream os(assembly);
+      spvModuleOp.print(os, OpPrintingFlags().useLocalScope());
+      dumpDataToPath(options.dumpIntermediatesPath, options.dumpBaseName,
+                     variantOp.getName(), ".mlir", assembly);
+    }
 
     // The runtime use ordinals instead of names but Metal requires function
     // names for constructing pipeline states. Get an ordered list of the entry

compiler/src/iree/compiler/Dialect/HAL/Target/WebGPU/WebGPUTarget.cpp

diff --git a/compiler/src/iree/compiler/Dialect/HAL/Target/WebGPU/WebGPUTarget.cpp b/compiler/src/iree/compiler/Dialect/HAL/Target/WebGPU/WebGPUTarget.cpp
index 0aee9c3..fdbc616 100644
--- a/compiler/src/iree/compiler/Dialect/HAL/Target/WebGPU/WebGPUTarget.cpp
+++ b/compiler/src/iree/compiler/Dialect/HAL/Target/WebGPU/WebGPUTarget.cpp
@@ -132,7 +132,15 @@
       return variantOp.emitError()
              << "should only contain exactly one spirv.module op";
     }
+
     auto spvModuleOp = *spirvModuleOps.begin();
+    if (!options.dumpIntermediatesPath.empty()) {
+      std::string assembly;
+      llvm::raw_string_ostream os(assembly);
+      spvModuleOp.print(os, OpPrintingFlags().useLocalScope());
+      dumpDataToPath(options.dumpIntermediatesPath, options.dumpBaseName,
+                     variantOp.getName(), ".mlir", assembly);
+    }
 
     // The schema expects each shader module to have entry points named "dN",
     // where N is the entry point ordinal.