test: update cases to silence 'var is never mutated' errors

test/cases/llvm/blocks.zig

@@ -5,6 +5,7 @@ fn assert(ok: bool) void {
 fn foo(ok: bool) i32 {
     const val: i32 = blk: {
         var x: i32 = 1;
+        _ = &x;
         if (!ok) break :blk x + 9;
         break :blk x + 19;
     };

test/cases/llvm/f_segment_address_space_reading_and_writing.zig

@@ -35,6 +35,7 @@ pub fn main() void {
     assert(getFs() == @intFromPtr(&test_value));
 
     var test_ptr: *allowzero addrspace(.fs) u64 = @ptrFromInt(0);
+    _ = &test_ptr;
     assert(test_ptr.* == 12345);
     test_ptr.* = 98765;
     assert(test_value == 98765);

test/cases/llvm/nested_blocks.zig

@@ -10,7 +10,7 @@ fn foo(ok: bool) i32 {
         };
         break :blk val2 + 10;
     };
-    return val;
+    return (&val).*;
 }
 
 pub fn main() void {

test/cases/llvm/optionals.zig

@@ -7,8 +7,10 @@ pub fn main() void {
     var null_val: ?i32 = null;
 
     var val1: i32 = opt_val.?;
+    _ = &val1;
     const val1_1: i32 = opt_val.?;
     var ptr_val1 = &(opt_val.?);
+    _ = &ptr_val1;
     const ptr_val1_1 = &(opt_val.?);
 
     var val2: i32 = null_val orelse 20;
@@ -16,9 +18,11 @@ pub fn main() void {
 
     var value: i32 = 20;
     var ptr_val2 = &(null_val orelse value);
+    _ = &ptr_val2;
 
     const val3 = opt_val orelse 30;
     var val3_var = opt_val orelse 30;
+    _ = &val3_var;
 
     assert(val1 == 10);
     assert(val1_1 == 10);

test/cases/llvm/simple_addition_and_subtraction.zig

@@ -4,6 +4,7 @@ fn add(a: i32, b: i32) i32 {
 
 pub fn main() void {
     var a: i32 = -5;
+    _ = &a;
     const x = add(a, 7);
     var y = add(2, 0);
     y -= x;