[Tests] Add missing willreturn attributes (NFC)

To retain the spirit of these tests after an upcoming change to mayHaveSideEffect(), add willreturn attributes to a number of functions.

Author: nikic

llvm/test/Transforms/LICM/funclet.ll

@@ -157,6 +157,6 @@ else: ; preds = %postinvoke
 
 declare void @may_throw()
 
-declare i32 @pure_computation() nounwind argmemonly readonly
+declare i32 @pure_computation() nounwind argmemonly readonly willreturn
 
 declare i32 @__CxxFrameHandler3(...)

llvm/test/Transforms/LICM/sinking.ll

@@ -3,7 +3,7 @@
 ; RUN: opt < %s -basic-aa -licm -S -enable-mssa-loop-dependency=true -verify-memoryssa | FileCheck %s
 
 
-declare i32 @strlen(i8*) readonly nounwind
+declare i32 @strlen(i8*) readonly nounwind willreturn
 
 declare void @foo()
 
@@ -27,7 +27,7 @@ Out:	; preds = %Loop
  ret i32 %A
 }
 
-declare double @sin(double) readnone nounwind
+declare double @sin(double) readnone nounwind willreturn
 
 ; Sink readnone function out of loop with unknown memory behavior.
 define double @test2(double %X) {

llvm/test/Transforms/SCCP/calltest.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -sccp -loop-deletion -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
-declare double @sqrt(double) readnone nounwind
+declare double @sqrt(double) readnone nounwind willreturn
 %empty = type {}
 declare %empty @has_side_effects()
 

llvm/test/Transforms/SCCP/musttail-call.ll

@@ -59,7 +59,7 @@ define internal i8* @side_effects(i8 %v) {
 }
 
 ; The call to this function is removed, so the return value must be zapped
-define internal i8* @no_side_effects(i8 %v) readonly nounwind {
+define internal i8* @no_side_effects(i8 %v) readonly nounwind willreturn {
 ; CHECK-LABEL: define {{[^@]+}}@no_side_effects
 ; CHECK-SAME: (i8 [[V:%.*]]) #[[ATTR0:[0-9]+]] {
 ; CHECK-NEXT: ret i8* undef

llvm/test/Transforms/SCCP/remove-call-inst.ll

@@ -15,7 +15,7 @@ entry:
  ret i32 %call2
 }
 
-define internal i32 @wwrite(i64 %i) nounwind readnone {
+define internal i32 @wwrite(i64 %i) nounwind readnone willreturn {
 ; CHECK-LABEL: @wwrite(
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT: br label [[SW_DEFAULT:%.*]]
@@ -36,4 +36,4 @@ return:
 }
 
 ; CHECK: attributes #0 = { noreturn nounwind }
-; CHECK: attributes #1 = { nounwind readnone }
+; CHECK: attributes #1 = { nounwind readnone willreturn }

llvm/test/Transforms/TailCallElim/reorder_load.ll

@@ -15,7 +15,7 @@ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 ; This load can be moved above the call because the function won't write to it
 ; and the call has no side effects.
-define fastcc i32 @raise_load_1(i32* %a_arg, i32 %a_len_arg, i32 %start_arg) nounwind readonly {
+define fastcc i32 @raise_load_1(i32* %a_arg, i32 %a_len_arg, i32 %start_arg) nounwind readonly willreturn {
 ; CHECK-LABEL: @raise_load_1(
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT: br label [[TAILRECURSE:%.*]]
@@ -99,7 +99,7 @@ recurse:	; preds = %else
 
 ; This load can be safely moved above the call (even though it's from an
 ; extern_weak global) because the call has no side effects.
-define fastcc i32 @raise_load_3(i32* %a_arg, i32 %a_len_arg, i32 %start_arg) nounwind readonly {
+define fastcc i32 @raise_load_3(i32* %a_arg, i32 %a_len_arg, i32 %start_arg) nounwind readonly willreturn {
 ; CHECK-LABEL: @raise_load_3(
 ; CHECK-NEXT: entry:
 ; CHECK-NEXT: br label [[TAILRECURSE:%.*]]