Shift error message now says "fixed-width integer type" instead of just "integer type" (#5028)

* error message of ir_analyze_bit_shift now more accurate/specific

* fixed compile error test to match bit shift error message

Author: foobles

src/ir.cpp

@@ -16974,7 +16974,7 @@ static IrInstGen *ir_analyze_bit_shift(IrAnalyze *ira, IrInstSrcBinOp *bin_op_in
 
         if (!instr_is_comptime(op2)) {
             ir_add_error(ira, &bin_op_instruction->base.base,
-                buf_sprintf("LHS of shift must be an integer type, or RHS must be compile-time known"));
+                buf_sprintf("LHS of shift must be a fixed-width integer type, or RHS must be compile-time known"));
             return ira->codegen->invalid_inst_gen;
         }
 

test/compile_errors.zig

@@ -5925,7 +5925,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\    return 0x11 << x;
         \\}
     , &[_][]const u8{
-        "tmp.zig:2:17: error: LHS of shift must be an integer type, or RHS must be compile-time known",
+        "tmp.zig:2:17: error: LHS of shift must be a fixed-width integer type, or RHS must be compile-time known",
     });
 
     cases.add("shifting RHS is log2 of LHS int bit width",