[browser][coreclr] ICU download

[dariatiurina]

This PR implements the choosing, downloading the proper ICU shard into the memory and then activating it.

Changes:

• Added new loadIcuData function in host.ts to allocate and initialize ICU.
• Added selection of the appropriate ICU shard logic into the runtime bootstrap process asset fetching and loading into the runtime bootstrap process after that calling the newly implemented loadIcuData function.
• Added coreclr_wasm_load_icu_data and related linkage functions to the ICU shim C file.
• Commented out ENV["DOTNET_SYSTEM_GLOBALIZATION_INVARIANT"] = "true"; in the libBrowserHost.footer.js and libCorerun.extpost.js allowing ICU-based globalization to be used when ICU data is loaded.

Resolves #120220

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Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
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[Copilot]

Pull request overview

This PR implements ICU (International Components for Unicode) data loading functionality for browser/CoreCLR, enabling proper globalization support with culture-specific ICU shards. The implementation adds logic to detect the appropriate ICU shard based on the user's culture, download it, allocate memory, and initialize it before CoreCLR startup.

• Adds ICU resource selection and sharding logic to automatically choose the appropriate ICU data file based on culture (EFIGS, CJK, or no-CJK shards)
• Implements loadIcuData function for memory allocation and ICU initialization via WASM interop
• Renames mono_wasm_load_icu_data to wasm_load_icu_data for runtime-agnostic naming across both Mono and CoreCLR

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/native/libs/System.Globalization.Native/pal_icushim_static.c	Renamed mono_wasm_load_icu_data to wasm_load_icu_data and updated comment references
src/native/libs/Common/JavaScript/types/internal.ts	Added wasm_load_icu_data method to EmscriptenModuleInternal interface
src/native/libs/Common/JavaScript/types/exchange.ts	Added loadIcuData to BrowserHostExports type definitions
src/native/libs/Common/JavaScript/cross-module/index.ts	Added loadIcuData to export table mapping
src/native/corehost/browserhost/loader/icu.ts	New file implementing ICU resource name selection and culture-based sharding logic
src/native/corehost/browserhost/loader/bootstrap.ts	Added ICU data fetching and loading to runtime bootstrap sequence
src/native/corehost/browserhost/libBrowserHost.footer.js	Commented out DOTNET_SYSTEM_GLOBALIZATION_INVARIANT to enable ICU globalization
src/native/corehost/browserhost/host/index.ts	Added loadIcuData export to BrowserHostExports table
src/native/corehost/browserhost/host/host.ts	Implemented loadIcuData function with memory allocation and WASM interop
src/mono/browser/runtime/icu.ts	Updated function name from mono_wasm_load_icu_data to wasm_load_icu_data
src/mono/browser/runtime/cwraps.ts	Updated cwraps signature for renamed function
src/mono/browser/runtime/assets.ts	Updated function call to use renamed wasm_load_icu_data
src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems	Added conditional compilation for CoreCLR-specific Interop.Locale file
src/libraries/Common/src/Interop/Unix/Interop.Libraries.cs	Added JavaScriptNative library constant
src/libraries/Common/src/Interop/Browser/Interop.Locale.CoreCLR.cs	New CoreCLR-specific locale interop using LibraryImport
src/coreclr/vm/wasm/callhelpers-reverse.cpp	Added CalendarData_EnumCalendarInfoCallback reverse thunk for globalization
src/coreclr/hosts/corerun/wasm/libCorerun.extpost.js	Commented out invariant globalization setting

[pavelsavara]

Good job, thanks for doing it!

[ilonatommy]

Great job!

[radekdoulik]

Great work. The reverse helper function will be regenerated, that should still work fine though.