Update `tint` to use new single entry point path for GLSL

Move the GLSL emission over to the new single entry point path and
remove the custom GLSL code for enforcing single entry point.

Bug: 380043961
Change-Id: I3bfe80b1c6d046c2ecaec52514d245f4c4e48d3e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/218316
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: James Price <jrprice@google.com>
diff --git a/test/tint/builtins/gen/literal/textureSampleLevel/1bf73e.wgsl.expected.glsl b/test/tint/builtins/gen/literal/textureSampleLevel/1bf73e.wgsl.expected.glsl
index c640653..a68adf2 100644
--- a/test/tint/builtins/gen/literal/textureSampleLevel/1bf73e.wgsl.expected.glsl
+++ b/test/tint/builtins/gen/literal/textureSampleLevel/1bf73e.wgsl.expected.glsl
@@ -1,3 +1,6 @@
+//
+// fragment_main
+//
 #version 460
 #extension GL_EXT_texture_shadow_lod: require
 precision highp float;
@@ -16,6 +19,9 @@
 void main() {
   v.inner = textureSampleLevel_1bf73e();
 }
+//
+// compute_main
+//
 #version 460
 #extension GL_EXT_texture_shadow_lod: require
 
@@ -33,6 +39,9 @@
 void main() {
   v.inner = textureSampleLevel_1bf73e();
 }
+//
+// vertex_main
+//
 #version 460
 #extension GL_EXT_texture_shadow_lod: require