writer/hlsl: Fix continuing block emission

Inline the `continuing` block in the places where `continue` is called.

Simplifies the emission, and fixes emission of `let` statements in the loop.

Also fix random indenting of intrinsic functions.

Fixed: tint:744
Fixed: tint:818
Change-Id: I06994dbc724bc646e0435a1035b00760eaf5f5ab
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51784
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/test/ptr_ref/load/local/ptr_private.wgsl.expected.hlsl b/test/ptr_ref/load/local/ptr_private.wgsl.expected.hlsl
index b3db42f..c28a1f3 100644
--- a/test/ptr_ref/load/local/ptr_private.wgsl.expected.hlsl
+++ b/test/ptr_ref/load/local/ptr_private.wgsl.expected.hlsl
@@ -1 +1,8 @@
-SKIP: Failed to generate: error: pointers not supported in HLSL
+static int i = 123;
+
+[numthreads(1, 1, 1)]
+void main() {
+  const int use = (i + 1);
+  return;
+}
+