feat: enable raw pointer return from scripts (FuelLabs#4341)

- This PR enables returning heap types from scripts.
- In FuelLabs/fuels-rs#848, support was added
for
returning vectors from smart contracts in the SDK, this safeguard can
now be
  removed so the same can happen with scripts.

sway-core/src/language/ty/program.rs

@@ -253,18 +253,6 @@ impl TyProgram {
                 // Directly returning a `raw_slice` is allowed, which will be just mapped to a RETD.
                 // TODO: Allow returning nested `raw_slice`s when our spec supports encoding DSTs.
                 let main_func = mains.remove(0);
-                if !main_func
-                    .return_type
-                    .type_id
-                    .extract_any_including_self(engines, &|type_info| {
-                        matches!(type_info, TypeInfo::RawUntypedPtr)
-                    })
-                    .is_empty()
-                {
-                    errors.push(CompileError::PointerReturnNotAllowedInMain {
-                        span: main_func.return_type.span.clone(),
-                    });
-                }
                 if !ty_engine
                     .get(main_func.return_type.type_id)
                     .extract_any(engines, &|type_info| {

sway-error/src/error.rs

@@ -594,8 +594,6 @@ pub enum CompileError {
     TypeNotAllowedInContractStorage { ty: String, span: Span },
     #[error("ref mut parameter not allowed for main()")]
     RefMutableNotAllowedInMain { param_name: Ident, span: Span },
-    #[error("Returning a `raw_ptr` from `main()` is not allowed.")]
-    PointerReturnNotAllowedInMain { span: Span },
     #[error(
         "Returning a type containing `raw_slice` from `main()` is not allowed. \
             Consider converting it into a flat `raw_slice` first."
@@ -793,7 +791,6 @@ impl Spanned for CompileError {
             ContractIdValueNotALiteral { span } => span.clone(),
             TypeNotAllowedInContractStorage { span, .. } => span.clone(),
             RefMutableNotAllowedInMain { span, .. } => span.clone(),
-            PointerReturnNotAllowedInMain { span } => span.clone(),
             NestedSliceReturnNotAllowedInMain { span } => span.clone(),
             InitializedRegisterReassignment { span, .. } => span.clone(),
             DisallowedControlFlowInstruction { span, .. } => span.clone(),

test/src/e2e_vm_tests/test_programs/should_fail/raw_ptr/raw_ptr_ret/Forc.toml → test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/raw_ptr_ret/Forc.toml

@@ -5,4 +5,4 @@ license = "Apache-2.0"
 name = "raw_ptr_ret"
 
 [dependencies]
-std = { path = "../../../../../../../sway-lib-std" }
+std = { path = "../../../../../../../../sway-lib-std" }

test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/raw_ptr_ret/src/main.sw

@@ -0,0 +1,9 @@
+script;
+
+use std::vec::Vec;
+
+fn main() -> raw_ptr {
+    let mut a : Vec<u64> = Vec::new();
+    a.push(1234);
+    a.buf.ptr
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/raw_ptr_ret/test.toml

@@ -0,0 +1,2 @@
+category = "run"
+expected_result = { action = "return", value = 67108854 }

test/src/e2e_vm_tests/test_programs/should_fail/raw_ptr/vec_ret/Forc.toml → test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/vec_ret/Forc.toml

@@ -5,4 +5,4 @@ license = "Apache-2.0"
 name = "vec_ret"
 
 [dependencies]
-std = { path = "../../../../../../../sway-lib-std" }
+std = { path = "../../../../../../../../sway-lib-std" }

test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/vec_ret/src/main.sw

@@ -0,0 +1,9 @@
+script;
+
+fn main() -> Vec<u64> {
+    let mut vec = Vec::new();
+    vec.push(124);
+    vec.push(124);
+    vec.push(124);
+    vec
+}

test/src/e2e_vm_tests/test_programs/should_pass/language/raw_ptr/vec_ret/test.toml

@@ -0,0 +1,2 @@
+category = "run"
+expected_result = { action = "return_data", value = "0000000003ffffc400000000000000040000000000000003" }