Avoid extra cast()s after CStr::as_ptr()

These used to be `&str` literals that did need a pointer cast, but that
became a no-op after switching to `c""` literals in #118566.

compiler/rustc_codegen_llvm/src/consts.rs

@@ -525,7 +525,7 @@ impl<'ll> CodegenCx<'ll, '_> {
                     let val = llvm::LLVMMetadataAsValue(self.llcx, meta);
                     llvm::LLVMAddNamedMetadataOperand(
                         self.llmod,
-                        c"wasm.custom_sections".as_ptr().cast(),
+                        c"wasm.custom_sections".as_ptr(),
                         val,
                     );
                 }