Contracts build risc-v fixtures (#2554)

Follow up from #2347 this time to verify that fixtures build to RISC-V

---------

Co-authored-by: alvicsam <alvicsam@gmail.com>
Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>
Co-authored-by: Alexander Theißen <alex.theissen@me.com>

substrate/frame/contracts/fixtures/build/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "contracts"
+version = "0.1.0"
+edition = "2021"
+
+# Binary targets are injected dynamically by the build script.
+[[bin]]
+
+# local path are injected dynamically by the build script.
+[dependencies]
+uapi = { package = 'pallet-contracts-uapi', path = "", default-features = false }
+common = { package = 'pallet-contracts-fixtures-common', path = "" }
+polkavm-derive = '0.2.0'
+
+[profile.release]
+opt-level = 3
+lto = true
+codegen-units = 1

substrate/frame/contracts/fixtures/build/riscv_memory_layout.ld

@@ -0,0 +1,4 @@
+SECTIONS {
+    .text : { KEEP(*(.text.polkavm_export)) }
+}
+