sem: Rename Vector::size() to Vector::Width()

`Size()` will be added which is the size of the type in bytes.

Change-Id: If997820d7859cd9d1bb0631d1b72150378e6a24b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59300
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/transform/decompose_memory_access.cc

@@ -153,7 +153,7 @@ bool IntrinsicDataTypeFor(const sem::Type* ty,
     return true;
   }
   if (auto* vec = ty->As<sem::Vector>()) {
-    switch (vec->size()) {
+    switch (vec->Width()) {
       case 2:
         if (vec->type()->Is<sem::I32>()) {
           out = DecomposeMemoryAccess::Intrinsic::DataType::kVec2I32;

src/transform/fold_constants.cc

@@ -56,7 +56,7 @@ void FoldConstants::Run(CloneContext& ctx, const DataMap&, DataMap&) {
     }
 
     if (auto* vec = ty->As<sem::Vector>()) {
-      uint32_t vec_size = static_cast<uint32_t>(vec->size());
+      uint32_t vec_size = static_cast<uint32_t>(vec->Width());
 
       // We'd like to construct the new vector with the same number of
       // constructor args that the original node had, but after folding

src/transform/robustness.cc

@@ -63,7 +63,7 @@ struct Robustness::State {
     Value size;              // size of the array, vector or matrix
     size.is_signed = false;  // size is always unsigned
     if (auto* vec = ret_type->As<sem::Vector>()) {
-      size.u32 = vec->size();
+      size.u32 = vec->Width();
 
     } else if (auto* arr = ret_type->As<sem::Array>()) {
       size.u32 = arr->Count();

src/transform/transform.cc

@@ -124,7 +124,7 @@ ast::Type* Transform::CreateASTTypeFor(CloneContext& ctx, const sem::Type* ty) {
   }
   if (auto* v = ty->As<sem::Vector>()) {
     auto* el = CreateASTTypeFor(ctx, v->type());
-    return ctx.dst->create<ast::Vector>(el, v->size());
+    return ctx.dst->create<ast::Vector>(el, v->Width());
   }
   if (auto* a = ty->As<sem::Array>()) {
     auto* el = CreateASTTypeFor(ctx, a->ElemType());

src/transform/vertex_pulling.cc

@@ -148,7 +148,7 @@ DataType DataTypeOf(sem::Type* ty) {
     return {BaseType::kF32, 1};
   }
   if (auto* vec = ty->As<sem::Vector>()) {
-    return {DataTypeOf(vec->type()).base_type, vec->size()};
+    return {DataTypeOf(vec->type()).base_type, vec->Width()};
   }
   return {BaseType::kInvalid, 0};
 }