Java and the CLR are not suitable targets for C or C++ compilation. Likewise with Python Bytecode.
Using LLVM is exactly what Google tried with PNaCl. It had a lot of drawbacks; WebAssembly is a much improved iteration of this idea.
Using LLVM is exactly what Google tried with PNaCl. It had a lot of drawbacks; WebAssembly is a much improved iteration of this idea.
Microsoft's original plan for CLR was to replace the complete Windows stack with .NET, they just failed to do, because not only they had to deal with technical issues, there were the internal wars from WinDev making sure that would never happen, hence the Longhorn failure, followed by the same ideas reborned as COM on Vista, rebooted as WinRT/UAP/UWP a couple of years later.
Microsoft even had something like LLVM, done on top of the CLR, called Phoenix. It just never came out of MSR into production.
https://en.wikipedia.org/wiki/Phoenix_(compiler_framework)
https://www.infoq.com/news/2008/05/Phoenix-Compiler-Framewor...
Also, GraalVM will happily consume LLVM bitcode.
Standard C++ compiles just fine.
There is no different than using language extensions on GCC, clang or any other C++ compilers.
You are not forced to use GC beyond the interop to other .NET languages.
I have integrated quite a few C++ libraries this way, given that my C++ experience makes it easier than having to deal with P/Invoke attributes and possible linking issues.
WASM exists mostly for political reasons as far as I can tell: it's something people who work on browsers can "own", vs outsource to other older teams with more historical baggage and different backing corporations. I mean, for WASM to be technically compelling you have to buy the idea that the best way to move the web forward is to enable applets-written-in-C without any useful form of DOM interop or GUI. That seems like a rather implausible claim.
As for embedding a JVM, sure, why not? Good JVMs are open source these days and HotSpot starts in 50 msec or less. V8 is very comparable, tech wise in terms of its approach. Lots of code out there targets JVM bytecode.
There are very good technical reasons for WASMs existence. JVM-Bytecode for example is very Java-focused, WASM doesn't need class-files or many bytecodes like invokevirtual. For supporting C++/Rust it doesn't even need GC.
Bringing large applications like PSDFKit, AutoCAD or games into the browser is certainly getting the web forward. Sure, WASM isn't intended for manipulating the DOM. This is still JS's job (at least for the foreseeable future).