[BasicAA] Add test for #126670 (NFC)

Author: nikic

llvm/test/Analysis/BasicAA/escape-source-aggregate.ll

@@ -0,0 +1,24 @@
+; RUN: opt -passes=aa-eval -print-all-alias-modref-info -disable-output 2>&1 <  %s | FileCheck %s
+
+declare { ptr, i1 } @get_struct()
+declare <2 x ptr> @get_vec()
+
+; CHECK: MayAlias: i32* %a, i32* %extract
+define i32 @test_extractvalue() {
+  %a = alloca i32
+  %call = call { ptr, i1 } @get_struct()
+  %extract = extractvalue { ptr, i1 } %call, 0
+  store i32 0, ptr %extract
+  %v = load i32, ptr %a
+  ret i32 %v
+}
+
+; CHECK: MayAlias: i32* %a, i32* %extract
+define i32 @test_extractelement() {
+  %a = alloca i32
+  %call = call <2 x ptr> @get_vec()
+  %extract = extractelement <2 x ptr> %call, i32 0
+  store i32 0, ptr %extract
+  %v = load i32, ptr %a
+  ret i32 %v
+}