Contracts move fixtures to new crate (#2246)

Small PR that introduce a new crate that will host RISC-V & wasm
fixtures for testing pallet-contracts

substrate/frame/contracts/fixtures/data/delegate_call_lib.wat

@@ -0,0 +1,79 @@
+(module
+	(import "seal0" "seal_set_storage" (func $seal_set_storage (param i32 i32 i32)))
+	(import "seal0" "seal_caller" (func $seal_caller (param i32 i32)))
+	(import "seal0" "seal_value_transferred" (func $seal_value_transferred (param i32 i32)))
+	(import "env" "memory" (memory 1 1))
+
+	;; [0, 32) storage key
+	(data (i32.const 0) "\01")
+
+	;; [32, 64) buffer for transferred value
+
+	;; [64, 96) size of the buffer for transferred value
+	(data (i32.const 64) "\20")
+
+	;; [96, 128) buffer for the caller
+
+	;; [128, 160) size of the buffer for caller
+	(data (i32.const 128) "\20")
+
+	(func $assert (param i32)
+		(block $ok
+			(br_if $ok
+				(get_local 0)
+			)
+			(unreachable)
+		)
+	)
+
+	(func (export "call")
+		;; place a value in storage
+		(call $seal_set_storage
+			(i32.const 0)		;; Pointer to storage key
+			(i32.const 0)		;; Pointer to value
+			(i32.const 32)		;; Size of value
+		)
+
+		;; This stores the value transferred in the buffer
+		(call $seal_value_transferred (i32.const 32) (i32.const 64))
+
+		;; assert len == 8
+		(call $assert
+			(i32.eq
+				(i32.load (i32.const 64))
+				(i32.const 8)
+			)
+		)
+
+		;; assert that contents of the buffer is equal to the value
+		;; passed to the `caller` contract: 1337
+		(call $assert
+			(i64.eq
+				(i64.load (i32.const 32))
+				(i64.const 1337)
+			)
+		)
+
+		;; fill the buffer with the caller.
+		(call $seal_caller (i32.const 96) (i32.const 128))
+
+		;; assert len == 32
+		(call $assert
+			(i32.eq
+				(i32.load (i32.const 128))
+				(i32.const 32)
+			)
+		)
+
+		;; assert that the first 64 byte are the beginning of "ALICE",
+		;; who is the caller of the `caller` contract
+		(call $assert
+			(i64.eq
+				(i64.load (i32.const 96))
+				(i64.const 0x0101010101010101)
+			)
+		)
+	)
+
+	(func (export "deploy"))
+)