Remove ghost_ prefix from ghost_instrumentation update entries

Author: sim642

src/witness/yamlWitness.ml

@@ -169,7 +169,7 @@ struct
   }
 
   let ghost_update' ~variable ~(expression): GhostInstrumentation.Update.t = {
-    ghost_variable = variable;
+    variable;
     expression;
   }
 

src/witness/yamlWitnessType.ml

@@ -518,22 +518,22 @@ struct
   module Update =
   struct
     type t = {
-      ghost_variable: string;
+      variable: string;
       expression: string;
     }
     [@@deriving eq, ord, hash]
 
-    let to_yaml {ghost_variable; expression} =
+    let to_yaml {variable; expression} =
       `O [
-        ("ghost_variable", `String ghost_variable);
+        ("variable", `String variable);
         ("expression", `String expression);
       ]
 
     let of_yaml y =
       let open GobYaml in
-      let+ ghost_variable = y |> find "ghost_variable" >>= to_string
+      let+ variable = y |> find "variable" >>= to_string
       and+ expression = y |> find "expression" >>= to_string in
-      {ghost_variable; expression}
+      {variable; expression}
   end
 
   module LocationUpdate =

tests/regression/13-privatized/74-mutex.t

@@ -186,7 +186,7 @@ Same with ghost_instrumentation and invariant_set entries.
         column: 5
         function: producer
       updates:
-      - ghost_variable: m_locked
+      - variable: m_locked
         expression: "1"
     - location:
         file_name: 74-mutex.c
@@ -195,7 +195,7 @@ Same with ghost_instrumentation and invariant_set entries.
         column: 5
         function: producer
       updates:
-      - ghost_variable: m_locked
+      - variable: m_locked
         expression: "0"
     - location:
         file_name: 74-mutex.c
@@ -204,7 +204,7 @@ Same with ghost_instrumentation and invariant_set entries.
         column: 3
         function: main
       updates:
-      - ghost_variable: multithreaded
+      - variable: multithreaded
         expression: "1"
     - location:
         file_name: 74-mutex.c
@@ -213,7 +213,7 @@ Same with ghost_instrumentation and invariant_set entries.
         column: 3
         function: main
       updates:
-      - ghost_variable: m_locked
+      - variable: m_locked
         expression: "1"
     - location:
         file_name: 74-mutex.c
@@ -222,7 +222,7 @@ Same with ghost_instrumentation and invariant_set entries.
         column: 3
         function: main
       updates:
-      - ghost_variable: m_locked
+      - variable: m_locked
         expression: "0"
   - entry_type: invariant_set
     content: