Handle PhiNode with edge==0 (#46388)

(cherry picked from commit fd66c30)

Author: martinholters

base/compiler/ssair/legacy.jl

@@ -58,7 +58,7 @@ function replace_code_newstyle!(ci::CodeInfo, ir::IRCode, nargs::Int)
         elseif isa(stmt, GotoIfNot)
             stmt = GotoIfNot(stmt.cond, first(ir.cfg.blocks[stmt.dest].stmts))
         elseif isa(stmt, PhiNode)
-            stmt = PhiNode(Int32[last(ir.cfg.blocks[edge].stmts) for edge in stmt.edges], stmt.values)
+            stmt = PhiNode(Int32[edge == 0 ? 0 : last(ir.cfg.blocks[edge].stmts) for edge in stmt.edges], stmt.values)
         elseif isa(stmt, Expr) && stmt.head === :enter
             stmt.args[1] = first(ir.cfg.blocks[stmt.args[1]::Int].stmts)
         end

test/compiler/inference.jl

@@ -4062,3 +4062,15 @@ end
 let t = Core.Compiler.tuple_tfunc(Any[Core.Const(42), Vararg{Any}])
     @test Core.Compiler.issimplertype(t, t)
 end
+
+# issue #45600
+@test only(code_typed() do
+    while true
+        x = try finally end
+    end
+end)[2] == Union{}
+@test only(code_typed() do
+    while true
+        @time 1
+    end
+end)[2] == Union{}