llvm-context: modularize compiler builtin functions (#234)

- Add the revive runtime function interface to minimize boiler plate
code.
- Outline heavily repeated code into dedicated functions to bring down
code size.
- The code size tests builds optimized for size.
- Function attributes are passed as slices.

This significantly brings down the code size for all OpenZeppelin wizard
contracts (using all possible features) compiled against OpenZeppelin
`v5.0.0` with size optimizations.

|contract|| `-Oz` main | `-Oz` PR || `-O3` main | `-O3` PR |
|-|-|-|-|-|-|-|
|erc1155.sol||100K|67K||114K|147K|
|erc20.sol||120K|90K||160K|191K|
|erc721.sol||128K|101K||178K|214K|
|governor.sol||226K|165K||293K|349K|
|rwa.sol||116K|85K||154K|185K|
|stable.sol||116K|86K||155K|192K|

On the flip side this introduces a heavy penalty for cycle optimized
builds. Setting the no-inline attributes for cycle optimized builds
helps a lot but heavily penalizes runtime speed (LLVM does not yet
inline everything properly - to be investigated later on).

Next steps:
- Modularize more functions
- Refactor the YUL function arguments to use pointers instead of values
- Afterwards check if LLVM still has trouble inline-ing properly on O3
or set the no-inline attribute if it does not penalize runtime
performance too bad.

crates/llvm-context/src/polkavm/context/function/mod.rs

@@ -81,8 +81,7 @@ impl<'ctx> Function<'ctx> {
             || (name.starts_with("__")
                 && name != self::runtime::FUNCTION_ENTRY
                 && name != self::runtime::FUNCTION_DEPLOY_CODE
-                && name != self::runtime::FUNCTION_RUNTIME_CODE
-                && name != self::runtime::FUNCTION_LOAD_IMMUTABLE_DATA)
+                && name != self::runtime::FUNCTION_RUNTIME_CODE)
     }
 
     /// Returns the LLVM function declaration.
@@ -110,30 +109,21 @@ impl<'ctx> Function<'ctx> {
     pub fn set_attributes(
         llvm: &'ctx inkwell::context::Context,
         declaration: Declaration<'ctx>,
-        attributes: Vec<Attribute>,
+        attributes: &[Attribute],
         force: bool,
     ) {
-        for attribute_kind in attributes.into_iter() {
+        for attribute_kind in attributes {
             match attribute_kind {
                 Attribute::Memory => unimplemented!("`memory` attributes are not implemented"),
                 attribute_kind @ Attribute::AlwaysInline if force => {
-                    let is_optimize_none_set = declaration
-                        .value
-                        .get_enum_attribute(
-                            inkwell::attributes::AttributeLoc::Function,
-                            Attribute::OptimizeNone as u32,
-                        )
-                        .is_some();
-                    if !is_optimize_none_set {
-                        declaration.value.remove_enum_attribute(
-                            inkwell::attributes::AttributeLoc::Function,
-                            Attribute::NoInline as u32,
-                        );
-                        declaration.value.add_attribute(
-                            inkwell::attributes::AttributeLoc::Function,
-                            llvm.create_enum_attribute(attribute_kind as u32, 0),
-                        );
-                    }
+                    declaration.value.remove_enum_attribute(
+                        inkwell::attributes::AttributeLoc::Function,
+                        Attribute::NoInline as u32,
+                    );
+                    declaration.value.add_attribute(
+                        inkwell::attributes::AttributeLoc::Function,
+                        llvm.create_enum_attribute(*attribute_kind as u32, 0),
+                    );
                 }
                 attribute_kind @ Attribute::NoInline if force => {
                     declaration.value.remove_enum_attribute(
@@ -142,12 +132,12 @@ impl<'ctx> Function<'ctx> {
                     );
                     declaration.value.add_attribute(
                         inkwell::attributes::AttributeLoc::Function,
-                        llvm.create_enum_attribute(attribute_kind as u32, 0),
+                        llvm.create_enum_attribute(*attribute_kind as u32, 0),
                     );
                 }
                 attribute_kind => declaration.value.add_attribute(
                     inkwell::attributes::AttributeLoc::Function,
-                    llvm.create_enum_attribute(attribute_kind as u32, 0),
+                    llvm.create_enum_attribute(*attribute_kind as u32, 0),
                 ),
             }
         }
@@ -178,27 +168,16 @@ impl<'ctx> Function<'ctx> {
         declaration: Declaration<'ctx>,
         optimizer: &Optimizer,
     ) {
-        if optimizer.settings().level_middle_end == inkwell::OptimizationLevel::None {
-            Self::remove_attributes(
-                declaration,
-                &[Attribute::OptimizeForSize, Attribute::AlwaysInline],
-            );
+        if optimizer.settings().level_middle_end_size == SizeLevel::Z {
             Self::set_attributes(
                 llvm,
                 declaration,
-                vec![Attribute::OptimizeNone, Attribute::NoInline],
-                false,
-            );
-        } else if optimizer.settings().level_middle_end_size == SizeLevel::Z {
-            Self::set_attributes(
-                llvm,
-                declaration,
-                vec![Attribute::OptimizeForSize, Attribute::MinSize],
+                &[Attribute::OptimizeForSize, Attribute::MinSize],
                 false,
             );
         }
 
-        Self::set_attributes(llvm, declaration, vec![Attribute::NoFree], false);
+        Self::set_attributes(llvm, declaration, &[Attribute::NoFree], false);
     }
 
     /// Sets the front-end runtime attributes.
@@ -208,7 +187,7 @@ impl<'ctx> Function<'ctx> {
         optimizer: &Optimizer,
     ) {
         if optimizer.settings().level_middle_end_size == SizeLevel::Z {
-            Self::set_attributes(llvm, declaration, vec![Attribute::NoInline], false);
+            Self::set_attributes(llvm, declaration, &[Attribute::NoInline], false);
         }
     }
 
@@ -220,7 +199,7 @@ impl<'ctx> Function<'ctx> {
         Self::set_attributes(
             llvm,
             declaration,
-            vec![
+            &[
                 Attribute::MustProgress,
                 Attribute::NoUnwind,
                 Attribute::WillReturn,