Fix value label ranges resolution (#1572)

There was a bug how value labels were resolved, which caused some DWARF expressions not be transformed, e.g. those are in the registers.

*    Implements FIXME in expression.rs
*    Move TargetIsa from CompiledExpression structure
*    Fix expression format for GDB
*    Add tests for parsing
*    Proper logic in ValueLabelRangesBuilder::process_label
*    Tests for ValueLabelRangesBuilder
*    Refactor build_with_locals to return Iterator instead of Vec<_>
*    Misc comments and magical numbers

crates/environ/src/data_structures.rs

@@ -5,7 +5,7 @@ pub mod ir {
         types, AbiParam, ArgumentPurpose, Signature, SourceLoc, StackSlots, TrapCode, Type,
         ValueLabel, ValueLoc,
     };
-    pub use cranelift_codegen::ValueLabelsRanges;
+    pub use cranelift_codegen::{ValueLabelsRanges, ValueLocRange};
 }
 
 pub mod settings {