Make DebugInfo edges per-call rather than per-callee

This is useful for when you need to, e.g., trim the "common prefix" of
two stacktraces that were both taken from inside an inlined function
call.

I'm hoping to use this property to provide a way to get only the
"popped" frames inside a `catch` handler, but that requires us to
understand when an inlined frame was popped, as in:
```julia
@inline function foo()
    try
        error("foo")
    catch err
        Base.showerror(stderr, err, Base.catch_backtrace())
    end
end
bar() = foo()
```

The popped frames would be:
```julia
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:44
 [2] foo
   @ ./REPL[1]:3 [inlined]
```

To know to trim off `bar()` (since it hasn't been popped yet), I want
to record the ip at catch entry and then have our stacktrace expansion
logic remove any frames common with the catch entry.

In order to trim that common prefix correctly, we need to distinguish
this case from:
```
try foo() catch foo() end
```
which has the same line number and callee, but is a different call.

base/compiler/ssair/inlining.jl

@@ -309,17 +309,11 @@ end
 # TODO append `inlinee_debuginfo` to inner linetable when `inlined_at[2] ≠ 0`
 function ir_inline_linetable!(debuginfo::DebugInfoStream, inlinee_debuginfo::DebugInfo, inlined_at::NTuple{3,Int32})
     # Append the linetable of the inlined function to our edges table
-    linetable_offset = 1
-    while true
-        if linetable_offset > length(debuginfo.edges)
-            push!(debuginfo.edges, inlinee_debuginfo)
-            break
-        elseif debuginfo.edges[linetable_offset] === inlinee_debuginfo
-            break
-        end
-        linetable_offset += 1
-    end
-    return (inlined_at[1], Int32(linetable_offset), Int32(0))
+    #
+    # We are not allowed to de-duplicate here, since we want to preserve the property that
+    # each DebugInfo edge corresponds to an inlined call (not just an inlined callee).
+    push!(debuginfo.edges, inlinee_debuginfo)
+    return (inlined_at[1], length(debuginfo.edges), Int32(0))
 end
 
 function ir_prepare_inlining!(insert_node!::Inserter, inline_target::Union{IRCode, IncrementalCompact},