Use a lambda for calls to ::open in RetryAfterSignal

In Bionic, open can be overloaded for _FORTIFY_SOURCE support, causing
compile errors of RetryAfterSignal due to overload resolution. Wrapping
the call in a lambda avoids this.

Based on a patch by Chih-Wei Huang <cwhuang@linux.org.tw>!

llvm-svn: 340751
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 3ca006a..ba483c8 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -774,8 +774,10 @@
 
   SmallString<128> Storage;
   StringRef P = Name.toNullTerminatedStringRef(Storage);
-  if ((ResultFD = sys::RetryAfterSignal(-1, ::open, P.begin(), OpenFlags, Mode)) <
-      0)
+  // Call ::open in a lambda to avoid overload resolution in RetryAfterSignal
+  // when open is overloaded, such as in Bionic.
+  auto Open = [&]() { return ::open(P.begin(), OpenFlags, Mode); };
+  if ((ResultFD = sys::RetryAfterSignal(-1, Open)) < 0)
     return std::error_code(errno, std::generic_category());
 #ifndef O_CLOEXEC
   if (!(Flags & OF_ChildInherit)) {
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
index fa515d4..3185f45 100644
--- a/llvm/lib/Support/Unix/Process.inc
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -211,7 +211,10 @@
     assert(errno == EBADF && "expected errno to have EBADF at this point!");
 
     if (NullFD < 0) {
-      if ((NullFD = RetryAfterSignal(-1, ::open, "/dev/null", O_RDWR)) < 0)
+      // Call ::open in a lambda to avoid overload resolution in
+      // RetryAfterSignal when open is overloaded, such as in Bionic.
+      auto Open = [&]() { return ::open("/dev/null", O_RDWR); };
+      if ((NullFD = RetryAfterSignal(-1, Open)) < 0)
         return std::error_code(errno, std::generic_category());
     }