* [wasm] Fix running merged test wrappers in runtime tests
- These were all getting removed because it looked for the incorrect
script path in case of wasm
* [wasm] Disable a multithreaded runtime test
```
Operation is not supported on this platform.
at System.Threading.Thread.ThrowIfNoThreadStart(Boolean internalThread)
at System.Threading.Thread.Start(Boolean captureContext, Boolean internalThread)
at System.Threading.Thread.Start()
at MutualThdRecur_fptr.main()
at Program.<>c__DisplayClass0_0.<<Main>$>g__TestExecutor29|30(TestFilter filter, StreamWriter tempLogSw, StreamWriter statsCsvSw)
```
* [wasm] Disable a failing test in JIT.Performance
`JIT/Performance/CodeQuality/Benchstones/MDBenchI/MDPuzzle/`
https://github.com/dotnet/runtime/issues/86772
* [wasm] Disable all JIT.Performance tests for now
<_MergedWrapperMarker Include="$(TestBinDir)**\*.MergedTestAssembly" Exclude="$(TestBinDir)**\supportFiles\*.MergedTestAssembly" />
<_MergedWrapperMarker Update="@(_MergedWrapperMarker)">
- <TestExecutionScriptPath>$([System.IO.Path]::ChangeExtension('%(Identity)', '.$(TestScriptExtension)'))</TestExecutionScriptPath>
+ <TestExecutionScriptPath Condition="'$(TargetsBrowser)' != 'true'">$([System.IO.Path]::ChangeExtension('%(Identity)', '.$(TestScriptExtension)'))</TestExecutionScriptPath>
+ <TestExecutionScriptPath Condition="'$(TargetsBrowser)' == 'true'">%(RootDir)%(Directory)AppBundle/RunTests.$(TestScriptExtension)</TestExecutionScriptPath>
</_MergedWrapperMarker>
<!-- Exclude merged test wrappers without the test execution script for this target (skipped due to CLRTestTargetUnsupported et al) -->
<ExcludeList Include = "$(XunitTestBinBase)/JIT/Regression/CLR-x86-JIT/V1-M13-RTM/b99969/b99969/**">
<Issue>https://github.com/dotnet/runtime/issues/41472</Issue>
</ExcludeList>
+ <ExcludeList Include = "$(XunitTestBinBase)/JIT/Directed/Misc/function_pointer/MutualThdRecur-fptr/**">
+ <Issue>https://github.com/dotnet/runtime/issues/41472</Issue>
+ </ExcludeList>
+ <!-- all JIT.performance disabled for now, due to https://github.com/dotnet/runtime/issues/86772 -->
+ <ExcludeList Include = "$(XunitTestBinBase)/JIT/Performance/**">
+ <Issue>https://github.com/dotnet/runtime/issues/86772</Issue>
+ </ExcludeList>
<ExcludeList Include = "$(XunitTestBinBase)/JIT/Methodical/VT/callconv/jumps4_r/**">
<Issue>needs triage</Issue>
</ExcludeList>