hail: update to common build.rs

This moves some flags from make to build.rs.

boards/Makefile.common

@@ -41,21 +41,10 @@ TARGET_DIRECTORY ?= $(TOCK_ROOT_DIRECTORY)target/
 # This will hopefully move into Cargo.toml (or Cargo.toml.local) eventually.
 #
 # - `relocation-model=static`: See https://github.com/tock/tock/pull/2853
-# - `-nmagic`: lld by default uses a default page size to align program
-#   sections. Tock expects that program sections are set back-to-back. `-nmagic`
-#   instructs the linker to not page-align sections.
-# - `-icf=all`: Identical Code Folding (ICF) set to all. This tells the linker
-#   to be more aggressive about removing duplicate code. The default is `safe`,
-#   and the downside to `all` is that different functions in the code can end up
-#   with the same address in the binary. However, it can save a fair bit of code
-#   size.
 RUSTC_FLAGS ?= \
-  -C link-arg=-Tlayout.ld \
   -C linker=rust-lld \
   -C linker-flavor=ld.lld \
   -C relocation-model=static \
-  -C link-arg=-nmagic \
-  -C link-arg=-icf=all \
 
 # RISC-V-specific flags.
 ifneq ($(findstring riscv32i, $(TARGET)),)

boards/hail/build.rs

@@ -1,5 +1,10 @@
+#[path = "../common_build.rs"]
+mod common_build;
+
 fn main() {
     println!("cargo:rerun-if-changed=layout.ld");
     println!("cargo:rerun-if-changed=chip_layout.ld");
     println!("cargo:rerun-if-changed=../kernel_layout.ld");
+
+    common_build::tock_default_linker_args();
 }