interpret: refactor function call handling to be better-abstracted

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -1,5 +1,6 @@
 //! An interpreter for MIR used in CTFE and by miri
 
+mod call;
 mod cast;
 mod discriminant;
 mod eval_context;
@@ -11,8 +12,8 @@ mod operand;
 mod operator;
 mod place;
 mod projection;
+mod stack;
 mod step;
-mod terminator;
 mod traits;
 mod util;
 mod validity;
@@ -22,7 +23,8 @@ use eval_context::{from_known_layout, mir_assign_valid_types};
 #[doc(no_inline)]
 pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here
 
-pub use self::eval_context::{format_interp_error, Frame, FrameInfo, InterpCx, StackPopCleanup};
+pub use self::call::FnArg;
+pub use self::eval_context::{format_interp_error, InterpCx};
 pub use self::intern::{
     intern_const_alloc_for_constprop, intern_const_alloc_recursive, HasStaticRootDefId, InternKind,
     InternResult,
@@ -35,7 +37,7 @@ pub use self::operand::{ImmTy, Immediate, OpTy, Readable};
 pub use self::place::{MPlaceTy, MemPlaceMeta, PlaceTy, Writeable};
 use self::place::{MemPlace, Place};
 pub use self::projection::{OffsetMode, Projectable};
-pub use self::terminator::FnArg;
+pub use self::stack::{Frame, FrameInfo, LocalState, StackPopCleanup, StackPopInfo};
 pub(crate) use self::util::create_static_alloc;
 pub use self::validity::{CtfeValidationMode, RefTracking};
 pub use self::visitor::ValueVisitor;