Implement function modifiers.

test/libsolidity/semanticTests/abiEncoderV2/abi_encode_v2_in_modifier_used_in_v1_contract.sol

@@ -34,5 +34,7 @@ contract C is B {
         return (x, y);
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // test() -> 5, 10

test/libsolidity/semanticTests/inlineAssembly/inline_assembly_in_modifiers.sol

@@ -28,6 +28,8 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> true
 // g() -> FAILURE

test/libsolidity/semanticTests/modifiers/break_in_modifier.sol

@@ -14,6 +14,8 @@ contract C {
         x = t;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // x() -> 0
 // f() ->

test/libsolidity/semanticTests/modifiers/continue_in_modifier.sol

@@ -14,6 +14,8 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // x() -> 0
 // f() ->

test/libsolidity/semanticTests/modifiers/function_modifier.sol

@@ -8,6 +8,8 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // getOne() -> 0
 // getOne(), 1 wei -> 1

test/libsolidity/semanticTests/modifiers/function_modifier_empty.sol

@@ -13,5 +13,7 @@ contract C is A {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> false

test/libsolidity/semanticTests/modifiers/function_modifier_library.sol

@@ -24,5 +24,7 @@ contract Test {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> 0x202

test/libsolidity/semanticTests/modifiers/function_modifier_library_inheritance.sol

@@ -30,5 +30,7 @@ contract Test {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> 0x202

test/libsolidity/semanticTests/modifiers/function_modifier_overriding.sol

@@ -15,5 +15,7 @@ contract C is A {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // f() -> false

test/libsolidity/semanticTests/modifiers/modifier_init_return.sol

@@ -0,0 +1,13 @@
+contract C {
+    modifier m(bool condition) {
+        if (condition) _;
+    }
+
+    function f(uint x) public m(x >= 10) returns (uint[5] memory r) {
+        r[2] = 3;
+    }
+}
+
+// ----
+// f(uint256): 9 -> 0x00, 0x00, 0x00, 0x00, 0x00
+// f(uint256): 10 -> 0x00, 0x00, 3, 0x00, 0x00

test/libsolidity/semanticTests/modifiers/return_does_not_skip_modifier.sol

@@ -10,6 +10,8 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // x() -> 0
 // f() -> 2

test/libsolidity/semanticTests/modifiers/return_in_modifier.sol

@@ -14,6 +14,8 @@ contract C {
     }
 }
 
+// ====
+// compileViaYul: also
 // ----
 // x() -> 0
 // f() ->

test/libsolidity/semanticTests/payable/no_nonpayable_circumvention_by_modifier.sol

@@ -13,6 +13,8 @@ contract C {
         return address(this).balance;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f(), 27 wei -> FAILURE
 // balance() -> 0

test/libsolidity/semanticTests/various/multi_modifiers.sol

@@ -16,6 +16,8 @@ contract C {
         x += 3;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f1() ->
 // x() -> 0x08