Teach AddressSanitizer to create basic blocks in a more natural order.
This is particularly useful to the backend code generators which try to
process things in the incoming function order.

Also, cleanup some uses of IRBuilder to be a bit simpler and more clear.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160254 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Instrumentation/AddressSanitizer/basic.ll b/test/Instrumentation/AddressSanitizer/basic.ll
index e80cfee..15b51d4 100644
--- a/test/Instrumentation/AddressSanitizer/basic.ll
+++ b/test/Instrumentation/AddressSanitizer/basic.ll
@@ -16,11 +16,6 @@
 ; CHECK:   icmp ne i8
 ; CHECK:   br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
 ;
-; The actual load comes next because ASan adds the last instrumentation block
-; to the end of the function.
-; CHECK:   %tmp1 = load i32* %a
-; CHECK:   ret i32 %tmp1
-;
 ; First instrumentation block refines the shadow test.
 ; CHECK:   and i64 %[[LOAD_ADDR]], 7
 ; CHECK:   add i64 %{{.*}}, 3
@@ -28,9 +23,13 @@
 ; CHECK:   icmp sge i8 %{{.*}}, %[[LOAD_SHADOW]]
 ; CHECK:   br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
 ;
-; Final instrumentation block reports the error.
+; Second instrumentation block reports the error.
 ; CHECK:   call void @__asan_report_load4(i64 %[[LOAD_ADDR]]) noreturn
 ; CHECK:   unreachable
+;
+; Finally the instrumented load.
+; CHECK:   %tmp1 = load i32* %a
+; CHECK:   ret i32 %tmp1
 
 entry:
   %tmp1 = load i32* %a
@@ -48,11 +47,6 @@
 ; CHECK:   icmp ne i8
 ; CHECK:   br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
 ;
-; The actual store comes next because ASan adds the last instrumentation block
-; to the end of the function.
-; CHECK:   store i32 42, i32* %a
-; CHECK:   ret void
-;
 ; First instrumentation block refines the shadow test.
 ; CHECK:   and i64 %[[STORE_ADDR]], 7
 ; CHECK:   add i64 %{{.*}}, 3
@@ -60,9 +54,13 @@
 ; CHECK:   icmp sge i8 %{{.*}}, %[[STORE_SHADOW]]
 ; CHECK:   br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
 ;
-; Final instrumentation block reports the error.
+; Second instrumentation block reports the error.
 ; CHECK:   call void @__asan_report_store4(i64 %[[STORE_ADDR]]) noreturn
 ; CHECK:   unreachable
+;
+; Finally the instrumented store.
+; CHECK:   store i32 42, i32* %a
+; CHECK:   ret void
 
 entry:
   store i32 42, i32* %a