WebAssembly support in LLDB

[JDevlieghere]

Meta-issue to track support for debugging WebAssembly (Wasm) using the GDB Remote Protocol with Wasm-specific extensions.

• Add WebAssembly Process Plugin and support backtraces.
• Automatically select the Wasm process plugin when connecting to a Wasm gdb stub.
• Add support for DW_OP_WASM_location.
• Document the qWasmCallStack, qWasmLocal, qWasmGlobal and qWasmStackValue packets.

[llvmbot]

@llvm/issue-subscribers-backend-webassembly

Author: Jonas Devlieghere (JDevlieghere)

Meta-issue to track support for debugging WebAssembly (Wasm) using the GDB Remote Protocol with Wasm-specific extensions.

[llvmbot]

@llvm/issue-subscribers-lldb

Author: Jonas Devlieghere (JDevlieghere)

Meta-issue to track support for debugging WebAssembly (Wasm) using the GDB Remote Protocol with Wasm-specific extensions.

[DavidSpickett]

Now linked from the website - c63c2f4.

[dschuff]

In case it's useful, the sources for Chrome's wasm debugging devtools extension can be found here, although there's unfortunately no good documentation. WasmVendorPlugins.cc defines wasm-specific integrations, although there are also some places where it uses private APIs that predate the plugins.