Fixes assert in type_check_encode_buffer_empty. (#6364)

## Description

Assert in type_check_encode_buffer_empty was causing the compiler to
crash.

We now throw a CompileError to avoid crashing.

Fixes #6338.

## Checklist

- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [ ] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

sway-core/src/semantic_analysis/ast_node/expression/intrinsic_function.rs

@@ -94,7 +94,7 @@ impl ty::TyIntrinsicFunctionKind {
                 type_check_contract_ret(handler, ctx, kind, arguments, type_arguments, span)
             }
             Intrinsic::EncodeBufferEmpty => {
-                type_check_encode_buffer_empty(ctx, kind, arguments, type_arguments, span)
+                type_check_encode_buffer_empty(handler, ctx, kind, arguments, type_arguments, span)
             }
             Intrinsic::EncodeBufferAppend => {
                 type_check_encode_append(handler, ctx, kind, arguments, type_arguments, span)
@@ -417,13 +417,20 @@ fn new_encoding_buffer_tuple(
 }
 
 fn type_check_encode_buffer_empty(
+    handler: &Handler,
     ctx: TypeCheckContext,
     kind: sway_ast::Intrinsic,
     arguments: &[Expression],
     _type_arguments: &[TypeArgument],
     span: Span,
 ) -> Result<(ty::TyIntrinsicFunctionKind, TypeId), ErrorEmitted> {
-    assert!(arguments.is_empty());
+    if !arguments.is_empty() {
+        return Err(handler.emit_err(CompileError::IntrinsicIncorrectNumArgs {
+            name: kind.to_string(),
+            expected: 0,
+            span,
+        }));
+    }
 
     let type_engine = ctx.engines.te();
     let engines = ctx.engines();

test/src/e2e_vm_tests/test_programs/should_fail/encode_buffer_empty_with_args/Forc.lock

@@ -0,0 +1,8 @@
+[[package]]
+name = "core"
+source = "path+from-root-BABDDF1B461AF6DA"
+
+[[package]]
+name = "encode_buffer_empty_with_args"
+source = "member"
+dependencies = ["core"]

test/src/e2e_vm_tests/test_programs/should_fail/encode_buffer_empty_with_args/Forc.toml

@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+license = "Apache-2.0"
+name = "encode_buffer_empty_with_args"
+entry = "main.sw"
+
+[dependencies]
+core = { path = "../../../../../../sway-lib-core" }

test/src/e2e_vm_tests/test_programs/should_fail/encode_buffer_empty_with_args/json_abi_oracle.json

@@ -0,0 +1 @@
+[]

test/src/e2e_vm_tests/test_programs/should_fail/encode_buffer_empty_with_args/src/main.sw

@@ -0,0 +1,13 @@
+library;
+
+struct Buffer {
+    buffer: (raw_ptr, u64, u64),
+}
+
+impl Buffer {
+    pub fn new() -> Self {
+        Buffer {
+            buffer: __encode_buffer_empty(self),
+        }
+    }
+}

test/src/e2e_vm_tests/test_programs/should_fail/encode_buffer_empty_with_args/test.toml

@@ -0,0 +1,4 @@
+category = "fail"
+
+# check: $()buffer: __encode_buffer_empty(self),
+# nextln: $()Call to "encode_buffer_empty" expects 0 arguments