fix(material/form-field): don't block click on prefix/suffix when disabled

Author: mmalerba

src/material/form-field/form-field.scss

@@ -63,10 +63,14 @@
   width: 100%;
 }
 
-// The MDC text-field should stretch to the width of the host `<mat-form-field>` element.
-// This allows developers to control the width without needing custom CSS overrides.
 .mat-mdc-text-field-wrapper {
+  // The MDC text-field should stretch to the width of the host `<mat-form-field>` element.
+  // This allows developers to control the width without needing custom CSS overrides.
   width: 100%;
+  // MDC applies the `.mdc-text-field--disabled` class to this element when the input is disabled.
+  // This breaks clicking on prefix and suffix buttons, so we override `pointer-events` to always
+  // allow clicking.
+  pointer-events: auto;
 }
 
 // Vertically center icons.