[clang][Driver][OpenBSD] libcxx also requires pthread

Author: brad0

clang/lib/Driver/ToolChains/OpenBSD.cpp

@@ -296,6 +296,7 @@ void OpenBSD::AddCXXStdlibLibArgs(const ArgList &Args,
 
   CmdArgs.push_back(Profiling ? "-lc++_p" : "-lc++");
   CmdArgs.push_back(Profiling ? "-lc++abi_p" : "-lc++abi");
+  CmdArgs.push_back(Profiling ? "-lpthread_p" : "-lpthread");
 }
 
 std::string OpenBSD::getCompilerRT(const ArgList &Args,

clang/test/Driver/openbsd.cpp

@@ -6,7 +6,7 @@
 // RUN:   | FileCheck --check-prefix=CHECK-CXX %s
 // RUN: %clangxx %s -### -o %t.o -target arm-unknown-openbsd 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-CXX %s
-// CHECK-CXX: "-lc++" "-lc++abi" "-lm"
+// CHECK-CXX: "-lc++" "-lc++abi" "-lpthread" "-lm"
 
 // RUN: %clangxx %s -### -pg -o %t.o -target amd64-pc-openbsd 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-PG-CXX %s
@@ -16,4 +16,4 @@
 // RUN:   | FileCheck --check-prefix=CHECK-PG-CXX %s
 // RUN: %clangxx %s -### -pg -o %t.o -target arm-unknown-openbsd 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-PG-CXX %s
-// CHECK-PG-CXX: "-lc++_p" "-lc++abi_p" "-lm_p"
+// CHECK-PG-CXX: "-lc++_p" "-lc++abi_p" "-lpthread_p" "-lm_p"