[WASM] Add ILStrip task to wasm app build process

[fanyang-mono]

Fixes #88696

With this PR, the customer is able to create an WASM app and enabling IL trimming for AOT compiled methods. By default, this is disabled. To enable it, build the app with WasmStripILAfterAOT =true. This change help producing a smaller WASM app.

Impact of this change is displayed as follows. I measured the size of _framework after compression using brotli for wasm apps with AOT enabled:

• Wasm app under src/mono/sample/wasm/browser
  • 6.0M -> 5.8M (-p:WasmEnableWebcil=false) (3.3% smaller)
  • 5.9M -> 5.8M (-p:WasmEnableWebcil=true) (1.7% smaller)
• Wasm app under src/mono/sample/wasm/browser-bench
  • 7.1M -> 6.8M (-p:WasmEnableWebcil=false) (4.2% smaller)
  • 7.1M -> 6.8M (-p:WasmEnableWebcil=true) (4.2% smaller)

[lewing]

Are we confident that this handles all the cases where wasm might transition to the interpreter appropriately?

[radical]

Also, test needed in src/mono/wasm/Wasm.Build.Tests.

[radical]

And could you please add some detail about what the PR is doing, like what the default is for the property, and what it will do, and/or affect?

[ghost]

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Issue Details

---

Fixes #88696

Author:	fanyang-mono
Assignees:	fanyang-mono
Labels:	arch-wasm, area-Build-mono
Milestone:	-

[lewing]

cc @kg

[fanyang-mono]

Are we confident that this handles all the cases where wasm might transition to the interpreter appropriately?

I am trying to test it with as many apps as I could get a hold on before merging it. TBH, I can't guarantee that this feature is going to work 100% for all wasm apps, that's why it is off by default.

[vargaz]

The mono changes look ok to me.

[lambdageek]

LGTM. Consider changing WASMStripIL to WasmStripIL.

Is it worth calling out that this only makes sense with AOT right in the property name? Maybe WasmStripILAfterAOT ?

[fanyang-mono]

Will enable WASM AOT tests with WasmStripILAfterAOT =true in a follow-up PR.