Move the segmented stack switch to a function attribute

This removes the -segmented-stacks command line flag in favor of a
per-function "split-stack" attribute.

Patch by Luqman Aden and Alex Crichton!

llvm-svn: 205997
diff --git a/llvm/test/CodeGen/Thumb/segmented-stacks.ll b/llvm/test/CodeGen/Thumb/segmented-stacks.ll
index 5649b00..89043ec 100644
--- a/llvm/test/CodeGen/Thumb/segmented-stacks.ll
+++ b/llvm/test/CodeGen/Thumb/segmented-stacks.ll
@@ -1,13 +1,13 @@
-; RUN: llc < %s -mtriple=thumb-linux-androideabi -segmented-stacks -verify-machineinstrs | FileCheck %s -check-prefix=Thumb-android
-; RUN: llc < %s -mtriple=thumb-linux-unknown-gnueabi -segmented-stacks -verify-machineinstrs | FileCheck %s -check-prefix=Thumb-linux
-; RUN: llc < %s -mtriple=thumb-linux-androideabi -segmented-stacks -filetype=obj
-; RUN: llc < %s -mtriple=thumb-linux-unknown-gnueabi -segmented-stacks -filetype=obj
+; RUN: llc < %s -mtriple=thumb-linux-androideabi -verify-machineinstrs | FileCheck %s -check-prefix=Thumb-android
+; RUN: llc < %s -mtriple=thumb-linux-unknown-gnueabi -verify-machineinstrs | FileCheck %s -check-prefix=Thumb-linux
+; RUN: llc < %s -mtriple=thumb-linux-androideabi -filetype=obj
+; RUN: llc < %s -mtriple=thumb-linux-unknown-gnueabi -filetype=obj
 
 
 ; Just to prevent the alloca from being optimized away
 declare void @dummy_use(i32*, i32)
 
-define void @test_basic() {
+define void @test_basic() #0 {
         %mem = alloca i32, i32 10
         call void @dummy_use (i32* %mem, i32 10)
 	ret void
@@ -54,7 +54,7 @@
 
 }
 
-define i32 @test_nested(i32 * nest %closure, i32 %other) {
+define i32 @test_nested(i32 * nest %closure, i32 %other) #0 {
        %addend = load i32 * %closure
        %result = add i32 %other, %addend
        ret i32 %result
@@ -101,7 +101,7 @@
 
 }
 
-define void @test_large() {
+define void @test_large() #0 {
         %mem = alloca i32, i32 10000
         call void @dummy_use (i32* %mem, i32 0)
         ret void
@@ -150,7 +150,7 @@
 
 }
 
-define fastcc void @test_fastcc() {
+define fastcc void @test_fastcc() #0 {
         %mem = alloca i32, i32 10
         call void @dummy_use (i32* %mem, i32 10)
         ret void
@@ -197,7 +197,7 @@
 
 }
 
-define fastcc void @test_fastcc_large() {
+define fastcc void @test_fastcc_large() #0 {
         %mem = alloca i32, i32 10000
         call void @dummy_use (i32* %mem, i32 0)
         ret void
@@ -245,3 +245,5 @@
 ; Thumb-linux:      pop     {r4, r5}
 
 }
+
+attributes #0 = { "split-stack" }