Only remove arg_count() method

kani-compiler/src/kani_middle/transform/body.rs

@@ -17,10 +17,14 @@ pub struct MutableBody {
 
  /// Declarations of locals within the function.
  ///
- /// The first local is the return value pointer, followed by locals for the function arguments,
- /// followed by any user-declared variables and temporaries.
+ /// The first local is the return value pointer, followed by `arg_count`
+ /// locals for the function arguments, followed by any user-declared
+ /// variables and temporaries.
  locals: Vec<LocalDecl>,
 
+ /// The number of arguments this function takes.
+ arg_count: usize,
+
  /// Debug information pertaining to user variables, including captures.
  var_debug_info: Vec<VarDebugInfo>,
 
@@ -54,6 +58,7 @@ impl MutableBody {
  pub fn from(body: Body) -> Self {
  MutableBody {
  locals: body.locals().to_vec(),
+ arg_count: body.arg_locals().len(),
  spread_arg: body.spread_arg(),
  blocks: body.blocks,
  var_debug_info: body.var_debug_info,
@@ -63,7 +68,14 @@ impl MutableBody {
 
  /// Create the new body consuming this mutable body.
  pub fn into(self) -> Body {
- Body::new(self.blocks, self.locals, self.var_debug_info, self.spread_arg, self.span)
+ Body::new(
+ self.blocks,
+ self.locals,
+ self.arg_count,
+ self.var_debug_info,
+ self.spread_arg,
+ self.span,
+ )
  }
 
  /// Add a new local to the body with the given attributes.