tint: Simplify ++/-- handling in transform

Now that we have untyped literals, we can just add `1` rather than
adding either `1u` or `1i`.

Bug: tint:1488
Change-Id: I59512be8fc67b1bf45088478da7c93bed37a69b8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/94141
Auto-Submit: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/src/tint/transform/expand_compound_assignment.cc b/src/tint/transform/expand_compound_assignment.cc
index d15d790..e5e953c 100644
--- a/src/tint/transform/expand_compound_assignment.cc
+++ b/src/tint/transform/expand_compound_assignment.cc
@@ -174,14 +174,8 @@
             state.Expand(assign, assign->lhs, ctx.Clone(assign->rhs), assign->op);
         } else if (auto* inc_dec = node->As<ast::IncrementDecrementStatement>()) {
             // For increment/decrement statements, `i++` becomes `i = i + 1`.
-            // TODO(jrprice): Simplify this when we have untyped literals.
-            auto* sem_lhs = ctx.src->Sem().Get(inc_dec->lhs);
-            const ast::IntLiteralExpression* one =
-                sem_lhs->Type()->UnwrapRef()->is_signed_integer_scalar()
-                    ? ctx.dst->Expr(1_i)->As<ast::IntLiteralExpression>()
-                    : ctx.dst->Expr(1_u)->As<ast::IntLiteralExpression>();
             auto op = inc_dec->increment ? ast::BinaryOp::kAdd : ast::BinaryOp::kSubtract;
-            state.Expand(inc_dec, inc_dec->lhs, one, op);
+            state.Expand(inc_dec, inc_dec->lhs, ctx.dst->Expr(1_a), op);
         }
     }
     state.Finalize();
diff --git a/src/tint/transform/expand_compound_assignment_test.cc b/src/tint/transform/expand_compound_assignment_test.cc
index 613a135..6b18b40 100644
--- a/src/tint/transform/expand_compound_assignment_test.cc
+++ b/src/tint/transform/expand_compound_assignment_test.cc
@@ -473,7 +473,7 @@
     auto* expect = R"(
 fn main() {
   var v : i32;
-  v = (v + 1i);
+  v = (v + 1);
 }
 )";
 
@@ -493,7 +493,7 @@
     auto* expect = R"(
 fn main() {
   var v : u32;
-  v = (v + 1u);
+  v = (v + 1);
 }
 )";
 
@@ -513,7 +513,7 @@
     auto* expect = R"(
 fn main() {
   var v : i32;
-  v = (v - 1i);
+  v = (v - 1);
 }
 )";
 
@@ -533,7 +533,7 @@
     auto* expect = R"(
 fn main() {
   var v : u32;
-  v = (v - 1u);
+  v = (v - 1);
 }
 )";
 
@@ -556,7 +556,7 @@
   var v : i32;
   let p = &(v);
   let tint_symbol = &(*(p));
-  *(tint_symbol) = (*(tint_symbol) + 1i);
+  *(tint_symbol) = (*(tint_symbol) + 1);
 }
 )";
 
@@ -584,7 +584,7 @@
 
 fn main() {
   var s : S;
-  s.m = (s.m + 1i);
+  s.m = (s.m + 1);
 }
 )";
 
@@ -617,7 +617,7 @@
 
 fn main() {
   let tint_symbol = &(a[idx()]);
-  *(tint_symbol) = (*(tint_symbol) + 1i);
+  *(tint_symbol) = (*(tint_symbol) + 1);
 }
 )";
 
@@ -651,7 +651,7 @@
 fn main() {
   let tint_symbol = &(v);
   let tint_symbol_1 = idx();
-  (*(tint_symbol))[tint_symbol_1] = ((*(tint_symbol))[tint_symbol_1] + 1i);
+  (*(tint_symbol))[tint_symbol_1] = ((*(tint_symbol))[tint_symbol_1] + 1);
 }
 )";
 
@@ -671,7 +671,7 @@
     auto* expect = R"(
 fn main() {
   var v : vec4<i32>;
-  v.y = (v.y + 1i);
+  v.y = (v.y + 1);
 }
 )";
 
@@ -727,7 +727,7 @@
     continuing {
       let tint_symbol = &(a[idx1()]);
       let tint_symbol_1 = idx2();
-      (*(tint_symbol))[tint_symbol_1] = ((*(tint_symbol))[tint_symbol_1] + 1i);
+      (*(tint_symbol))[tint_symbol_1] = ((*(tint_symbol))[tint_symbol_1] + 1);
     }
   }
 }