Sema: remove incorrect safety check for saturating left shift

Author: Justus2308

src/Sema.zig

@@ -13677,7 +13677,7 @@ fn zirShl(
     try sema.requireRuntimeBlock(block, src, runtime_src);
     if (block.wantSafety()) {
         const bit_count = scalar_ty.intInfo(zcu).bits;
-        if (!std.math.isPowerOfTwo(bit_count)) {
+        if (air_tag != .shl_sat and !std.math.isPowerOfTwo(bit_count)) {
             const bit_count_val = try pt.intValue(scalar_rhs_ty, bit_count);
             const ok = if (rhs_ty.zigTypeTag(zcu) == .vector) ok: {
                 const bit_count_inst = Air.internedToRef((try sema.splat(rhs_ty, bit_count_val)).toIntern());

test/behavior/bit_shifting.zig

@@ -170,8 +170,6 @@ test "Saturating Shift Left" {
 
     const S = struct {
         fn shlSat(x: anytype, y: std.math.Log2Int(@TypeOf(x))) @TypeOf(x) {
-            // workaround https://github.com/ziglang/zig/issues/23033
-            @setRuntimeSafety(false);
             return x <<| y;
         }
 

test/behavior/x86_64/binary.zig

@@ -5473,8 +5473,6 @@ inline fn shlSaturate(comptime Type: type, lhs: Type, rhs: Type) Type {
         // workaround https://github.com/ziglang/zig/issues/23139
         return lhs <<| @min(@abs(rhs), splat(ChangeScalar(Type, u64), imax(u64)));
     }
-    // workaround https://github.com/ziglang/zig/issues/23033
-    @setRuntimeSafety(false);
     return lhs <<| @abs(rhs);
 }
 test shlSaturate {