Normalize all line endings to LF

And force shader code to always use LF endings.

Post merge, there were a number of files that crept in with CRLF endings.

Some Tint end-to-end tests take objection to CRLF endings.

CRLF endings can be detected with:

```
git grep -I --files-with-matches --perl-regexp '\r' HEAD
```

And fixed with:

```
find . -type f -exec dos2unix {} \;
```

Bug: dawn:1339
Change-Id: Iee054bafd15875de744b86e28393cd8229bd3cfa
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86140
Kokoro-Run: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>

test/tint/statements/switch/common.wgsl

@@ -1,20 +1,20 @@
-@stage(compute) @workgroup_size(1)
-fn f() {
-    var i : i32;
-    var result : i32;
-    switch(i) {
-        case 0: {
-            result = 10;
-        }
-        case 1: {
-            result = 22;
-        }
-        case 2: {
-            result = 33;
-        }
-        default: {
-            result = 44;
-            break;
-        }
-    }
-}
+@stage(compute) @workgroup_size(1)
+fn f() {
+    var i : i32;
+    var result : i32;
+    switch(i) {
+        case 0: {
+            result = 10;
+        }
+        case 1: {
+            result = 22;
+        }
+        case 2: {
+            result = 33;
+        }
+        default: {
+            result = 44;
+            break;
+        }
+    }
+}

test/tint/statements/switch/only_default_case.wgsl

@@ -1,11 +1,11 @@
-@stage(compute) @workgroup_size(1)
-fn f() {
-    var i : i32;
-    var result : i32;
-    switch(i) {
-        default: {
-            result = 44;
-            break;
-        }
-    }
-}
+@stage(compute) @workgroup_size(1)
+fn f() {
+    var i : i32;
+    var result : i32;
+    switch(i) {
+        default: {
+            result = 44;
+            break;
+        }
+    }
+}