Add streamlined CoreCLR WebAssembly documentation with essential build and debug workflows

docs/workflow/building/coreclr/README.md

@@ -91,6 +91,12 @@ Using an x64 machine, it is possible to generate builds for other architectures.
 
 Detailed instructions on how to do cross-compilation can be found in the cross-building doc [over here](/docs/workflow/building/coreclr/cross-building.md).
 
+### Platform-Specific Guides
+
+For specialized platforms, detailed instructions are available in the following guides:
+
+- **WebAssembly:** [Building CoreCLR for WebAssembly](/docs/workflow/building/coreclr/wasm.md) - Experimental support for building, running, and debugging CoreCLR on WebAssembly.
+
 ## Other Features
 
 ### Build Drivers

docs/workflow/building/coreclr/wasm.md

@@ -0,0 +1,118 @@
+# Building CoreCLR for WebAssembly
+
+This guide provides instructions for building, running, and debugging CoreCLR on WebAssembly (WASM). This is experimental support and is currently under active development.
+
+## Table of Contents
+
+- [Prerequisites](#prerequisites)
+- [Building CoreCLR for WebAssembly](#building-coreclr-for-webassembly)
+- [Testing the Runtime](#testing-the-runtime)
+- [Debugging](#debugging)
+  - [Chrome DevTools with DWARF Support](#chrome-devtools-with-dwarf-support)
+  - [VS Code WebAssembly Debugging](#vs-code-webassembly-debugging)
+
+## Prerequisites
+
+Make sure you've prepared your environment and installed all the requirements for your platform. If not, follow this [link](/docs/workflow/README.md#introduction) for the corresponding instructions.
+
+## Building CoreCLR for WebAssembly
+
+To build the CoreCLR runtime for WebAssembly, use the following command from the repository root:
+
+**Linux/macOS:**
+```bash
+./build.sh -os browser -c Debug -subset clr.runtime
+```
+
+**Windows:**
+```cmd
+.\build.cmd -os browser -c Debug -subset clr.runtime
+```
+
+This command will:
+- Install the Emscripten SDK (emsdk) automatically
+- Build the CoreCLR runtime for WebAssembly
+- Build the required libraries
+
+**Note:** The first build may take longer as it downloads and sets up the Emscripten toolchain.
+
+## Testing the Runtime
+
+### Browser Testing (Recommended)
+
+If you don't have `dotnet-serve` installed, you can install it as a global .NET tool with:
+
+```bash
+dotnet tool install --global dotnet-serve
+```
+
+**Linux/macOS:**
+```bash
+dotnet-serve --directory "artifacts/bin/coreclr/browser.wasm.Debug/corewasmrun"
+```
+
+**Windows:**
+```cmd
+dotnet-serve --directory "artifacts\bin\coreclr\browser.wasm.Debug\corewasmrun"
+```
+
+This will start a local HTTP server and you can open the provided URL in your browser.
+
+### Console Testing
+
+You can also run the runtime directly in Node.js:
+
+```bash
+cd artifacts/bin/coreclr/browser.wasm.Debug/corewasmrun/
+node corewasmrun.js
+```
+
+## Debugging
+
+### Chrome DevTools with DWARF Support
+
+For debugging CoreCLR WebAssembly code, the recommended approach is using Chrome browser with the **C/C++ DevTools Support (DWARF)** extension:
+
+1. **Install the Chrome extension:**
+   - [C/C++ DevTools Support (DWARF)](https://chrome.google.com/webstore/detail/cc-devtools-support-dwar/odljcjlcidgdhcjhoijagojpnjcgocgd)
+
+2. **Open Chrome DevTools** (F12) while running your WebAssembly application
+
+3. **Set breakpoints** in the Sources tab:
+   - Navigate to the WebAssembly modules
+   - You can step through C code, set breakpoints, and inspect WebAssembly linear memory
+   - The extension provides source-level debugging with DWARF debug information
+
+**Note:** The debugging experience is not perfect but works most of the time. You can step through C code, set breakpoints, and inspect the WebAssembly linear memory.
+
+### VS Code WebAssembly Debugging
+
+VS Code, through Node.js, provides a good debugging option for WebAssembly CoreCLR:
+
+1. **Install the VS Code extension (Optional):**
+   - [WebAssembly Dwarf Debugging](https://marketplace.visualstudio.com/items?itemName=ms-vscode.wasm-dwarf-debugging)
+
+2. **Create a launch.json configuration:**
+   ```json
+   {
+       "version": "0.2.0",
+       "configurations": [
+           {
+               "type": "node",
+               "request": "launch",
+               "name": "corewasmrun",
+               "skipFiles": [
+                   "<node_internals>/**"
+               ],
+               "program": "corewasmrun.js",
+               "cwd": "${workspaceFolder}/artifacts/bin/coreclr/browser.wasm.Debug/corewasmrun/"
+           }
+       ]
+   }
+   ```
+
+3. **Set breakpoints** in `corewasmrun.js` in one of the `put_char` functions (the `stdout`/`stderr` implementation)
+
+4. **Start debugging** and step through the WebAssembly code using the call stack
+
+This approach allows you to debug the JavaScript host and step into WebAssembly code or into the C/C++ code if the Dwarf Debugging extension was installed.