rustdoc: fix tooltip position of code examples inside warning blocks

The tooltip of an `ignore`/`compile_fail`/`should_panic`/edition example
is placed 25px to the left of the code block. Inside a `.warning` block
that lands on top of the warning's own left border.

src/librustdoc/html/static/css/rustdoc.css

@@ -1818,6 +1818,12 @@ documentation. */
 .top-doc > .docblock >.warning:first-child::before {
 	top: 20px;
 }
+.content .docblock .warning .example-wrap.compile_fail,
+.content .docblock .warning .example-wrap.should_panic,
+.content .docblock .warning .example-wrap.ignore,
+.content .docblock .warning .example-wrap.edition {
+	margin-left: 25px;
+}
 
 .example-wrap > a.test-arrow, .example-wrap .button-holder {
 	visibility: hidden;

tests/rustdoc-gui/src/test_docs/lib.rs

@@ -108,6 +108,14 @@ impl From<u32> for Foo {
 }
 
 /// <div id="doc-warning-0" class="warning">I have warnings!</div>
+///
+/// <div id="doc-warning-3" class="warning">
+///
+/// ```ignore (it's a test)
+/// let x = 12;
+/// ```
+///
+/// </div>
 pub struct WarningStruct;
 
 /// Just a normal enum.

tests/rustdoc-gui/warning-block.goml

@@ -53,3 +53,11 @@ go-to: "file://" + |DOC_PATH| + "/test_docs/struct.WarningStruct.html"
 store-position: ("#doc-warning-0", {"y": warn_div_y})
 store-position: ("#doc-warning-0::before", {"y": warn_y})
 assert: |warn_y| == |warn_div_y| + |default_y_pos| + 15
+
+// The tooltip of a code example inside a warning must not overlap the warning's left border.
+store-position: ("#doc-warning-3", {"x": warn_x})
+store-position: ("#doc-warning-3 .example-wrap", {"x": code_x})
+store-position: ("#doc-warning-3 .example-wrap .tooltip", {"x": tooltip_x})
+store-size: ("#doc-warning-3 .example-wrap .tooltip", {"width": tooltip_width})
+assert: |tooltip_x| > |warn_x| + 2
+assert: |tooltip_x| + |tooltip_width| < |code_x|