Revert storage of method instance in LineInfoNode (#50546)

Due to #50082, reverting the causative portion from #41099, which stored
MethodInstances in LineInfoNodes.

(cherry picked from commit ae798cd)

base/compiler/ssair/inlining.jl

@@ -330,7 +330,7 @@ function ir_inline_linetable!(linetable::Vector{LineInfoNode}, inlinee_ir::IRCod
     # Append the linetable of the inlined function to our line table
     topline::Int32 = linetable_offset + Int32(1)
     coverage_by_path = JLOptions().code_coverage == 3
-    push!(linetable, LineInfoNode(inlinee_def.module, inlinee, inlinee_def.file, inlinee_def.line, inlined_at))
+    push!(linetable, LineInfoNode(inlinee_def.module, inlinee_def.name, inlinee_def.file, inlinee_def.line, inlined_at))
     oldlinetable = inlinee_ir.linetable
     extra_coverage_line = zero(Int32)
     for oldline in eachindex(oldlinetable)

base/compiler/typeinfer.jl

@@ -1015,7 +1015,7 @@ function typeinf_ext(interp::AbstractInterpreter, mi::MethodInstance)
             tree.slotflags = fill(IR_FLAG_NULL, nargs)
             tree.ssavaluetypes = 1
             tree.codelocs = Int32[1]
-            tree.linetable = LineInfoNode[LineInfoNode(method.module, mi, method.file, method.line, Int32(0))]
+            tree.linetable = LineInfoNode[LineInfoNode(method.module, method.name, method.file, method.line, Int32(0))]
             tree.ssaflags = UInt8[0]
             set_inlineable!(tree, true)
             tree.parent = mi

test/stacktraces.jl

@@ -91,9 +91,16 @@ trace = (try; f(3); catch; stacktrace(catch_backtrace()); end)[1:3]
 can_inline = Bool(Base.JLOptions().can_inline)
 for (frame, func, inlined) in zip(trace, [g,h,f], (can_inline, can_inline, false))
     @test frame.func === typeof(func).name.mt.name
-    @test frame.linfo.def.module === which(func, (Any,)).module
-    @test frame.linfo.def === which(func, (Any,))
-    @test frame.linfo.specTypes === Tuple{typeof(func), Int}
+    # broken until #50082 can be addressed
+    if inlined
+        @test frame.linfo.def.module === which(func, (Any,)).module broken=true
+        @test frame.linfo.def === which(func, (Any,)) broken=true
+        @test frame.linfo.specTypes === Tuple{typeof(func), Int} broken=true
+    else
+        @test frame.linfo.def.module === which(func, (Any,)).module
+        @test frame.linfo.def === which(func, (Any,))
+        @test frame.linfo.specTypes === Tuple{typeof(func), Int}
+    end
     # line
     @test frame.file === Symbol(@__FILE__)
     @test !frame.from_c