inference: follow up JuliaLang#49260, remove no longer necessary functions (JuliaLang#55430)

Author: aviatesk

base/compiler/inferencestate.jl

@@ -517,72 +517,6 @@ function compute_trycatch(code::Vector{Any}, bbs::Union{Vector{BasicBlock},Nothi
     return handler_info
 end
 
-function is_throw_call(e::Expr, code::Vector{Any})
-    if e.head === :call
-        f = e.args[1]
-        if isa(f, SSAValue)
-            f = code[f.id]
-        end
-        if isa(f, GlobalRef)
-            ff = abstract_eval_globalref_type(f)
-            if isa(ff, Const) && ff.val === Core.throw
-                return true
-            end
-        end
-    end
-    return false
-end
-
-function mark_throw_blocks!(src::CodeInfo, handler_info::Union{Nothing,HandlerInfo})
-    for stmt in find_throw_blocks(src.code, handler_info)
-        src.ssaflags[stmt] |= IR_FLAG_THROW_BLOCK
-    end
-    return nothing
-end
-
-# this utility function is incomplete and won't catch every block that always throws, since:
-# - it only recognizes direct calls to `throw` within the target code, so it can't mark
-#   blocks that deterministically call `throw` internally, like those containing `error`.
-# - it just does a reverse linear traverse of statements, there's a chance it might miss
-#   blocks, particularly when there are reverse control edges.
-function find_throw_blocks(code::Vector{Any}, handler_info::Union{Nothing,HandlerInfo})
-    stmts = BitSet()
-    n = length(code)
-    for i in n:-1:1
-        s = code[i]
-        if isa(s, Expr)
-            if s.head === :gotoifnot
-                if i+1 in stmts && s.args[2]::Int in stmts
-                    push!(stmts, i)
-                end
-            elseif s.head === :return
-                # see `ReturnNode` handling
-            elseif is_throw_call(s, code)
-                if handler_info === nothing || handler_info.handler_at[i][1] == 0
-                    push!(stmts, i)
-                end
-            elseif i+1 in stmts
-                push!(stmts, i)
-            end
-        elseif isa(s, ReturnNode)
-            # NOTE: it potentially makes sense to treat unreachable nodes
-            # (where !isdefined(s, :val)) as `throw` points, but that can cause
-            # worse codegen around the call site (issue #37558)
-        elseif isa(s, GotoNode)
-            if s.label in stmts
-                push!(stmts, i)
-            end
-        elseif isa(s, GotoIfNot)
-            if i+1 in stmts && s.dest in stmts
-                push!(stmts, i)
-            end
-        elseif i+1 in stmts
-            push!(stmts, i)
-        end
-    end
-    return stmts
-end
-
 # check if coverage mode is enabled
 function should_insert_coverage(mod::Module, debuginfo::DebugInfo)
     coverage_enabled(mod) && return true