pw_polyfill: C++11 and C++14 unit tests

Change-Id: I1a1ced2ed59a3d7dcf46c4c6a0e2e04485502fba
diff --git a/pw_build/BUILD.gn b/pw_build/BUILD.gn
index b5ad0be..9383f60 100644
--- a/pw_build/BUILD.gn
+++ b/pw_build/BUILD.gn
@@ -38,6 +38,14 @@
   cflags_cc = [ "-Wnon-virtual-dtor" ]
 }
 
+config("cpp11") {
+  cflags_cc = [ "-std=c++11" ]
+}
+
+config("cpp14") {
+  cflags_cc = [ "-std=c++14" ]
+}
+
 config("cpp17") {
   cflags_cc = [
     "-std=c++17",
diff --git a/pw_polyfill/BUILD.gn b/pw_polyfill/BUILD.gn
index 7b0dd5d..85c1125 100644
--- a/pw_polyfill/BUILD.gn
+++ b/pw_polyfill/BUILD.gn
@@ -66,7 +66,11 @@
 }
 
 pw_test_group("tests") {
-  tests = [ ":default_cpp_test" ]
+  tests = [
+    ":default_cpp_test",
+    ":cpp11_test",
+    ":cpp14_test",
+  ]
 }
 
 pw_test("default_cpp_test") {
@@ -78,6 +82,26 @@
   ]
 }
 
+pw_test("cpp11_test") {
+  configs = [ "$dir_pw_build:cpp11" ]
+  sources = [
+    "test.cc",
+  ]
+  deps = [
+    ":pw_polyfill",
+  ]
+}
+
+pw_test("cpp14_test") {
+  configs = [ "$dir_pw_build:cpp14" ]
+  sources = [
+    "test.cc",
+  ]
+  deps = [
+    ":pw_polyfill",
+  ]
+}
+
 pw_doc_group("docs") {
   sources = [
     "docs.rst",