Avoid memsets for constant collections where possible

• Analysis to determine which collection constants actually need to be memset to zero.
• NoResetConstant schedule to encode analysis result persistently.
• Use NoResetConstant in backends to not generate memsets.

hercules_cg/src/cpu.rs

@@ -288,13 +288,15 @@ impl<'a> CPUContext<'a> {
                         self.get_value(id, false),
                         offset.idx()
                     )?;
-                    let data_size = self.codegen_type_size(self.typing[id.idx()], body)?;
-                    write!(
-                        body,
-                        "  call void @llvm.memset.p0.i64({}, i8 0, i64 {}, i1 false)\n",
-                        self.get_value(id, true),
-                        data_size,
-                    )?;
+                    if !self.function.schedules[id.idx()].contains(&Schedule::NoResetConstant) {
+                        let data_size = self.codegen_type_size(self.typing[id.idx()], body)?;
+                        write!(
+                            body,
+                            "  call void @llvm.memset.p0.i64({}, i8 0, i64 {}, i1 false)\n",
+                            self.get_value(id, true),
+                            data_size,
+                        )?;
+                    }
                 }
             }
             Node::DynamicConstant { id: dc_id } => {