Expand Whale scalar support and remove unused std::libc bindings

std/POLICY.md

@@ -4,9 +4,13 @@ This document defines non-negotiable rules for the Wave standard library (`std/`
 
 ## 1) Layering Rules
 
-- `std/libc/**` is the only directory allowed to declare `extern(c)`.
-- Outside `std/libc/**`, modules must use Wave code and/or `std/sys/**` raw syscall wrappers.
-- High-level modules (`std/io`, `std/fs`, `std/net`, `std/process`, `std/mem`, etc.) must not import `std::libc::*`.
+- General-purpose C library bindings belong in external libraries, not `std/`.
+- `extern(c)` declarations are limited to the target-specific C ABI providers
+  explicitly approved by `tools/check_std_policy.py`. This includes hosted OS
+  APIs and WASI imports; it does not require replacing existing OS bindings.
+- Portable modules use Wave code and the target-selected `std/sys/**` provider
+  surface. No standard library module may import the removed `std::libc::*`
+  binding modules.
 
 ## 2) Syntax Rules
 
@@ -37,6 +41,6 @@ Run:
 
 The checker validates:
 
-- `extern(c)` appears only under `std/libc/**`
-- no `std::libc::*` import outside `std/libc/**`
+- `extern(c)` appears only in explicitly approved target C ABI providers
+- no `std::libc::*` import in standard library modules
 - no retired `let` or `let mut` declarations in Wave sources

std/README.md

@@ -16,7 +16,7 @@ licensed under the repository's [Mozilla Public License 2.0](../LICENSE).
 
 ## Dependency Policy
 
-- General-purpose `extern(c)` bindings belong under `std/libc/*`.
+- General-purpose C library bindings are not bundled with the standard library.
 - Target providers under `std/sys/*` may use the small set of hosted C ABI
   bindings explicitly approved by `tools/check_std_policy.sh` when the OS does
   not expose an equivalent stable raw syscall contract.
@@ -25,9 +25,15 @@ licensed under the repository's [Mozilla Public License 2.0](../LICENSE).
   environment access, process exit, and linear-memory allocation. The allocator
   is also available to bare `wasm32-unknown-unknown` modules. A separate
   Memory64 allocator backs `wasm64-unknown-unknown` without narrowing pointers.
-- Modules outside `std/libc/*` must not import `std::libc::*`; portable modules
+- Standard library modules must not import `std::libc::*`; portable modules
   depend on the target-independent `std::sys::*` provider surface instead.
 
+The former `std::libc::*` binding modules have been removed during alpha
+development. Existing imports of these modules no longer resolve. Use the
+relevant Wave standard library APIs, or provide C interoperability bindings in
+an external library for the required target ABI. The target providers under
+`std::sys::*` retain their existing OS API bindings.
+
 ## Core Modules
 
 - `std::time`: portable clocks and sleep, normalized durations, UTC calendar