Add test triggered by review discussion on D97077

Author: preames

llvm/test/Analysis/ScalarEvolution/ranges.ll

@@ -21,6 +21,23 @@ define i32 @ashr(i32 %a) {
   ret i32 %ashr
 }
 
+; Highlight the fact that non-argument non-instructions are
+; also possible.
+@G = external global i8
+define i64 @ashr_global() {
+; CHECK-LABEL: 'ashr_global'
+; CHECK-NEXT:  Classifying expressions for: @ashr_global
+; CHECK-NEXT:    %ashr = ashr i64 ptrtoint (i8* @G to i64), 63
+; CHECK-NEXT:    --> %ashr U: [-1,1) S: [-1,1)
+; CHECK-NEXT:  Determining loop execution counts for: @ashr_global
+;
+  %ashr = ashr i64 ptrtoint (i8* @G to i64), 63
+  %pos = icmp sge i8* @G, null
+  call void @llvm.assume(i1 %pos)
+  ret i64 %ashr
+}
+
+
 define i32 @shl(i32 %a) {
 ; CHECK-LABEL: 'shl'
 ; CHECK-NEXT:  Classifying expressions for: @shl