behavior: correct tests after ziglang#18816

test/behavior/generics.zig

@@ -371,8 +371,12 @@ test "extern function used as generic parameter" {
     const S = struct {
         extern fn usedAsGenericParameterFoo() void;
         extern fn usedAsGenericParameterBar() void;
-        inline fn usedAsGenericParameterBaz(comptime _: anytype) type {
-            return struct {};
+        inline fn usedAsGenericParameterBaz(comptime token: anytype) type {
+            return struct {
+                comptime {
+                    _ = token;
+                }
+            };
         }
     };
     try expect(S.usedAsGenericParameterBaz(S.usedAsGenericParameterFoo) !=

test/behavior/src.zig

@@ -23,8 +23,12 @@ test "@src" {
 
 test "@src used as a comptime parameter" {
     const S = struct {
-        fn Foo(comptime _: std.builtin.SourceLocation) type {
-            return struct {};
+        fn Foo(comptime src: std.builtin.SourceLocation) type {
+            return struct {
+                comptime {
+                    _ = src;
+                }
+            };
         }
     };
     const T1 = S.Foo(@src());

test/behavior/typename.zig

@@ -164,21 +164,30 @@ test "fn param" {
 }
 
 fn TypeFromFn(comptime T: type) type {
-    _ = T;
-    return struct {};
+    return struct {
+        comptime {
+            _ = T;
+        }
+    };
 }
 
 fn TypeFromFn2(comptime T1: type, comptime T2: type) type {
-    _ = T1;
-    _ = T2;
-    return struct {};
+    return struct {
+        comptime {
+            _ = T1;
+            _ = T2;
+        }
+    };
 }
 
 fn TypeFromFnB(comptime T1: type, comptime T2: type, comptime T3: type) type {
-    _ = T1;
-    _ = T2;
-    _ = T3;
-    return struct {};
+    return struct {
+        comptime {
+            _ = T1;
+            _ = T2;
+            _ = T3;
+        }
+    };
 }
 
 /// Replaces integers in `actual` with '0' before doing the test.