Move allocator to libtock_core

Cargo.toml

diff --git a/Cargo.toml b/Cargo.toml
index 50c20ef..51e49db 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,13 +6,12 @@
 edition = "2018"
 
 [features]
-alloc = [ "linked_list_allocator" ]
+alloc = ["libtock-core/alloc"]
 
 [dependencies]
 core = { package = "async-support", path = "async-support" }
 libtock-core = { path = "core" }
 libtock_codegen = { path = "codegen" }
-linked_list_allocator = { optional = true, version = "=0.6.5", default-features = false }
 futures = { version = "0.3.1", default-features = false, features = ["unstable", "cfg-target-has-atomic"] }
 
 [dev-dependencies]

core/Cargo.toml

diff --git a/core/Cargo.toml b/core/Cargo.toml
index 6f300f4..b154552 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -6,4 +6,8 @@
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[features]
+alloc = [ "linked_list_allocator" ]
+
 [dependencies]
+linked_list_allocator = { optional = true, version = "=0.6.5", default-features = false }
\ No newline at end of file

core/src/alloc.rs

diff --git a/src/alloc.rs b/core/src/alloc.rs
similarity index 100%
rename from src/alloc.rs
rename to core/src/alloc.rs

core/src/lib.rs

diff --git a/core/src/lib.rs b/core/src/lib.rs
index c8ffa54..e465f4d 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -1,6 +1,9 @@
 #![feature(asm, lang_items, naked_functions)]
 #![cfg_attr(any(target_arch = "arm", target_arch = "riscv32"), no_std)]
+#![cfg_attr(feature = "alloc", feature(alloc_error_handler))]
 
+#[cfg(feature = "alloc")]
+mod alloc;
 mod entry_point;
 #[cfg(any(target_arch = "arm", target_arch = "riscv32"))]
 mod lang_items;

src/lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 2ff6cca..0aabb1a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,5 @@
-#![cfg_attr(feature = "alloc", feature(alloc_error_handler))]
 #![cfg_attr(any(target_arch = "arm", target_arch = "riscv32"), no_std)]
 
-#[cfg(feature = "alloc")]
-mod alloc;
-
 pub mod adc;
 pub mod ble_composer;
 pub mod ble_parser;