Update Test Check duplicates global check lines.

[jdoerfert]

Since https://reviews.llvm.org/D148216 global check lines are not cleared properly:

cat test.ll
-----------                                                                                                                                                                             
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
; RUN: opt -S < %s | FileCheck %s

@G = constant i32 42

;.
; CHECK: @G = constant i32 42
;.
define ptr @foo() {
; CHECK-LABEL: define ptr @foo() {
; CHECK-NEXT:    ret ptr @G
;
  ret ptr @G
}

./llvm/utils/update_test_checks.py --check-globals=all test.ll

cat test.ll
-----------                                                                                                                                                                             
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
; RUN: opt -S < %s | FileCheck %s

@G = constant i32 42

; CHECK: @G = constant i32 42
;.
; CHECK: @G = constant i32 42
;.
define ptr @foo() {
; CHECK-LABEL: define ptr @foo() {
; CHECK-NEXT:    ret ptr @G
;
  ret ptr @G
}

./llvm/utils/update_test_checks.py --check-globals=all test.ll

cat test.ll
-----------                                                                                                                                                                             
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
; RUN: opt -S < %s | FileCheck %s

@G = constant i32 42

; CHECK: @G = constant i32 42
; CHECK: @G = constant i32 42
;.
; CHECK: @G = constant i32 42
;.
define ptr @foo() {
; CHECK-LABEL: define ptr @foo() {
; CHECK-NEXT:    ret ptr @G
;
  ret ptr @G
}

[jdoerfert]

This also groups unnamed and named globals, which does not work without -DAG:

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
; RUN: opt -S %s | FileCheck %s

@0 = private unnamed_addr constant i32 0
@named1 = weak constant i8 1
@1 = private unnamed_addr constant i32 2
@named2 = weak constant i8 3

declare void @use(ptr)
define void @test() {
  call void @use(ptr @0)
  call void @use(ptr @named1)
  call void @use(ptr @1)
  call void @use(ptr @named2)
  ret void
}

results in

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals
; RUN: opt -S %s | FileCheck %s

@0 = private unnamed_addr constant i32 0
@named1 = weak constant i8 1
@1 = private unnamed_addr constant i32 2
@named2 = weak constant i8 3

declare void @use(ptr)
;.
; CHECK: @[[GLOB0:[0-9]+]] = private unnamed_addr constant i32 0
; CHECK: @[[GLOB1:[0-9]+]] = private unnamed_addr constant i32 2
;.
; CHECK: @named1 = weak constant i8 1
; CHECK: @named2 = weak constant i8 3
;.
define void @test() {
; CHECK-LABEL: @test(
; CHECK-NEXT:    call void @use(ptr @[[GLOB0]])
; CHECK-NEXT:    call void @use(ptr @named1)
; CHECK-NEXT:    call void @use(ptr @[[GLOB1]])
; CHECK-NEXT:    call void @use(ptr @named2)
; CHECK-NEXT:    ret void
;
  call void @use(ptr @0)
  call void @use(ptr @named1)
  call void @use(ptr @1)
  call void @use(ptr @named2)
  ret void
}

which cannot be verified (due to the order).