[Sema] Reword unused lambda capture warning

Summary:
The warning doesn't know why the variable was looked up but not
odr-used, so reword it to not claim that it was used in an unevaluated
context.

Reviewers: aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28902

llvm-svn: 292498
diff --git a/clang/test/SemaCXX/warn-unused-lambda-capture.cpp b/clang/test/SemaCXX/warn-unused-lambda-capture.cpp
index 18c5d64..f4b1c92 100644
--- a/clang/test/SemaCXX/warn-unused-lambda-capture.cpp
+++ b/clang/test/SemaCXX/warn-unused-lambda-capture.cpp
@@ -22,6 +22,7 @@
 
 void test() {
   int i = 0;
+  const int k = 0;
 
   auto captures_nothing = [] {};
 
@@ -34,8 +35,9 @@
   auto explicit_by_value_used = [i] { return i + 1; };
   auto explicit_by_value_used_void = [i] { (void)i; };
   auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}
-  auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for use in an unevaluated context}}
-  auto explicit_by_value_unused_decltype = [i] { decltype(i) j = 0; }; // expected-warning{{lambda capture 'i' is not required to be captured for use in an unevaluated context}}
+  auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}
+  auto explicit_by_value_unused_decltype = [i] { decltype(i) j = 0; }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}
+  auto explicit_by_value_unused_const = [k] { return k + 1; };         // expected-warning{{lambda capture 'k' is not required to be captured for this use}}
 
   auto explicit_by_reference_used = [&i] { i++; };
   auto explicit_by_reference_unused = [&i] {}; // expected-warning{{lambda capture 'i' is not used}}
@@ -70,6 +72,7 @@
 template <typename T>
 void test_templated() {
   int i = 0;
+  const int k = 0;
 
   auto captures_nothing = [] {};
 
@@ -82,8 +85,9 @@
   auto explicit_by_value_used = [i] { return i + 1; };
   auto explicit_by_value_used_void = [i] { (void)i; };
   auto explicit_by_value_unused = [i] {}; // expected-warning{{lambda capture 'i' is not used}}
-  auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for use in an unevaluated context}}
+  auto explicit_by_value_unused_sizeof = [i] { return sizeof(i); }; // expected-warning{{lambda capture 'i' is not required to be captured for this use}}
   auto explicit_by_value_unused_decltype = [i] { decltype(i) j = 0; }; // expected-warning{{lambda capture 'i' is not used}}
+  auto explicit_by_value_unused_const = [k] { return k + 1; };         // expected-warning{{lambda capture 'k' is not required to be captured for this use}}
 
   auto explicit_by_reference_used = [&i] { i++; };
   auto explicit_by_reference_unused = [&i] {}; // expected-warning{{lambda capture 'i' is not used}}