[cxx-interop] Pull over fix from 8e7766b and apply to strstr, sin, and cos.

Author: zoecarver

lib/ClangImporter/ImportDecl.cpp

@@ -3206,7 +3206,9 @@ namespace {
           // instead of checking if they come from the `std` module.
           if (!d->getDeclName().isIdentifier())
             return false;
-          return d->getName() == "abs" || d->getName() == "div";
+          return d->getName() == "abs" || d->getName() == "div" ||
+              d->getName() == "strstr" || d->getName() == "sin" ||
+              d->getName() == "cos";
         };
         if (decl->getOwningModule() &&
             (decl->getOwningModule()
@@ -3217,7 +3219,8 @@ namespace {
               Impl.getClangPreprocessor().getSourceManager().getFilename(
                   decl->getLocation());
           if (filename.endswith("cmath") || filename.endswith("math.h") ||
-              filename.endswith("stdlib.h") || filename.endswith("cstdlib")) {
+              filename.endswith("stdlib.h") || filename.endswith("cstdlib") ||
+              filename.endswith("string.h")) {
             return nullptr;
           }
         }

test/Interop/Cxx/stdlib/avoid-import-cxx-math.swift

@@ -20,4 +20,5 @@ func test() {
 
     let _ = CxxStdlib.abs(x) // expected-error {{module 'CxxStdlib' has no member named 'abs'}}
     let _ = CxxStdlib.div(x) // expected-error {{module 'CxxStdlib' has no member named 'div'}}
+    let _ = CxxStdlib.strstr("a", "aaa") // expected-error {{module 'CxxStdlib' has no member named 'strstr'}}
 }