[ci-scan] Test failure: Regression_o_2 browser-wasm R2R platform incompatibilities

## Build Information
Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581938
Build error leg or test failing: `coreclr Pri1 Runtime Tests Run browser wasm checked R2R_CG2` - `Regression_o_2`
Pull request: https://github.com/dotnet/runtime/pull/133206
Console log: https://helixr1107v0xdcypoyl9e7f.blob.core.windows.net/dotnet-runtime-refs-pull-133206-merge-a3b88aaf22c042c488/Regression_o_2/1/console.442a0e08.log?helixlogtype=result

KBE authoring guidance (ci-failure-scan)

- `Error Details` is for readers. The exception excerpts below identify both failures from the merged work item.
- Build Analysis parses only the JSON block under `Error Message`.
- `ErrorMessage` uses ordered, case-sensitive ordinal `String.Contains` matches copied from the failing log.
- This is deterministic test coverage, not an infrastructure retry case.

## Error Details

```text
Running test: global::Runtime_117566.TestEntryPoint()
System.ArgumentException: Path "" is not an absolute path. (Parameter 'assemblyPath')
at System.Runtime.Loader.AssemblyLoadContext.LoadFromAssemblyPath(String assemblyPath)
at Runtime_117566.TestEntryPoint()
Failed test: global::Runtime_117566.TestEntryPoint()

Running test: global::Runtime_58874.Runtime_58874.TestEntryPoint()
System.DllNotFoundException: Unable to load shared library 'kernel32' or one of its dependencies.
dynamic linking not enabled
at Runtime_58874.Runtime_58874.EndOfPage.Create()
at Runtime_58874.Runtime_58874.TestEntryPoint()
Failed test: global::Runtime_58874.Runtime_58874.TestEntryPoint()
```

## Likely Cause

PR #133134 added the parallel browser-wasm ReadyToRun lane that Crossgen2-compiles and executes merged regression runners. Its merge commit is present in this build, and the new lane now executes `Regression_o_2` under browser-wasm R2R.

`Runtime_117566` assumes `Assembly.GetExecutingAssembly().Location` is a usable file path. Browser-wasm assemblies have no location, so the value is empty by design and `LoadFromAssemblyPath` rejects it.

`Runtime_58874` contains a `kernel32` allocation path and fails resolving that native library in browser-wasm, where dynamic linking is unavailable.

These tests need browser-wasm/ReadyToRun applicability guards or equivalent platform-safe setup before the merged runner can pass in the new lane.

## Error Message

```json
{
"ErrorMessage": [
"global::Runtime_117566.TestEntryPoint()",
"Path \"\" is not an absolute path.",
"global::Runtime_58874.Runtime_58874.TestEntryPoint()",
"dynamic linking not enabled"
],
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

Agentic workflow metadata (ci-failure-scan)

Workflow artifact: ci-failure-scan
Artifact kind: kbe-verification
Verified match count: 1 console log

> [!NOTE]
> This issue was prepared with GitHub Copilot assistance and reviewed by the submitting developer.

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581938
**Error message validated:** `[global::Runtime_117566.TestEntryPoint() Path "" is not an absolute path. global::Runtime_58874.Runtime_58874.TestEntryPoint() dynamic linking not enabled`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 9/4/2026 8:31:28 PM UTC

### Report

|Build|Repository|Test|Pull Request|
|---|---|---|---|
|[1583554](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583554)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583554&view=ms.vss-test-web.build-test-results-tab&runId=43692070&resultId=100508)|dotnet/runtime#131826|
|[1583511](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583511)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583511&view=ms.vss-test-web.build-test-results-tab&runId=43691516&resultId=100504)|dotnet/runtime#133253|
|[1583514](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583514)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583514&view=ms.vss-test-web.build-test-results-tab&runId=43691466&resultId=101072)|dotnet/runtime#133252|
|[1583502](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583502)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583502&view=ms.vss-test-web.build-test-results-tab&runId=43691290&resultId=101014)|dotnet/runtime#133215|
|[1583460](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583460)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583460&view=ms.vss-test-web.build-test-results-tab&runId=43690644&resultId=101315)|dotnet/runtime#133248|
|[1583457](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583457)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583457&view=ms.vss-test-web.build-test-results-tab&runId=43690592&resultId=100419)|dotnet/runtime#133213|
|[1581938](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581938)|dotnet/runtime|[global::Runtime_58874.Runtime_58874.TestEntryPoint()](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581938&view=ms.vss-test-web.build-test-results-tab&runId=43640036&resultId=100453)|dotnet/runtime#133206|
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|7|7|7|