InlineAssembly: Extracting tests for variable declaration

test/libyul/yulSyntaxTests/vardecl.yul

@@ -0,0 +1,5 @@
+{
+    let x := 7
+}
+// ====
+// dialect: yul

test/libyul/yulSyntaxTests/vardecl_bool.yul

@@ -0,0 +1,6 @@
+{
+    let x := true
+    let y := false
+}
+// ====
+// dialect: evm

test/libyul/yulSyntaxTests/vardecl_complex.yul

@@ -0,0 +1,4 @@
+{
+    let y := 2
+    let x := add(add(7, mul(6, y)), mul(7, 8))
+}

test/libyul/yulSyntaxTests/vardecl_empty.yul

@@ -0,0 +1,3 @@
+{
+	let x
+}

test/libyul/yulSyntaxTests/vardecl_multi.yul

@@ -0,0 +1,4 @@
+{
+    function f() -> x, y {}
+    let x, y := f()
+}

test/libyul/yulSyntaxTests/vardecl_multi_conflict.yul

@@ -0,0 +1,6 @@
+{
+	function f() -> x, y {}
+	let x, x := f()
+}
+// ----
+// DeclarationError 1395: (28-43): Variable name x already taken in this scope.

test/libyul/yulSyntaxTests/vardecl_name_clashes.yul

@@ -0,0 +1,6 @@
+{
+	let x := 1
+	let x := 2
+}
+// ----
+// DeclarationError 1395: (15-25): Variable name x already taken in this scope.

test/libyul/yulSyntaxTests/variable_use_before_decl_1.yul

@@ -0,0 +1,6 @@
+{
+	x := 2
+	let x := 3
+}
+// ----
+// DeclarationError 1133: (3-4): Variable x used before it was declared.

test/libyul/yulSyntaxTests/variable_use_before_decl_2.yul

@@ -0,0 +1,6 @@
+{
+	let x := mul(2, x)
+}
+
+// ----
+// DeclarationError 4990: (19-20): Variable x used before it was declared.