Change vectorlike from struct to union

* src/lisp.h (vectorlike_headed): Change from struct to union.
All uses changed.  Since it has only one member, this does not
change semantics.  This is designed to simplify future changes
needed to fix bugs like Bug#29040.  All uses changed.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/font.h b/src/font.h
index 8f2e27f0edd..43d6f67e3e9 100644
--- a/src/font.h
+++ b/src/font.h
@@ -244,7 +244,7 @@ enum font_property_index
 
 struct font_spec
 {
-  struct vectorlike_header header;
+  union vectorlike_header header;
   Lisp_Object props[FONT_SPEC_MAX];
 };
 
@@ -252,7 +252,7 @@ struct font_spec
 
 struct font_entity
 {
-  struct vectorlike_header header;
+  union vectorlike_header header;
   Lisp_Object props[FONT_ENTITY_MAX];
 };
 
@@ -265,7 +265,7 @@ struct font_entity
 
 struct font
 {
-  struct vectorlike_header header;
+  union vectorlike_header header;
 
   /* All Lisp_Object components must come first.
      That ensures they are all aligned normally.  */