[mips][ias] Enable IAS by default for OpenBSD / FreeBSD mips64/mips64el.

[brad]

Summary

Enable IAS by default for OpenBSD / FreeBSD mips64/mips64el.

[brad]

Sorry wrong revision of the diff.

[atanasyan]

LGTM, but before commit please add a test case into the freebsd.c.

lib/Driver/ToolChains/Gnu.cpp

bool Generic_GCC::IsIntegratedAssemblerDefault() const {
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64:
   case llvm::Triple::systemz:
   case llvm::Triple::mips:
   case llvm::Triple::mipsel:
     return true;
   case llvm::Triple::mips64:
   case llvm::Triple::mips64el:
-    // Enabled for Debian and Android mips64/mipsel, as they can precisely
-    // identify the ABI in use (Debian) or only use N64 for MIPS64 (Android).
-    // Other targets are unable to distinguish N32 from N64.
+    // Enabled for Debian, Android, FreeBSD and OpenBSD mips64/mipsel, as they
+    // can precisely identify the ABI in use (Debian) or only use N64 for MIPS64
+    // (Android). Other targets are unable to distinguish N32 from N64.
     if (getTriple().getEnvironment() == llvm::Triple::GNUABI64 ||
-        getTriple().isAndroid())
+        getTriple().isAndroid() ||
+        getTriple().isOSOpenBSD() ||
+        getTriple().isOSFreeBSD())
       return true;
     return false;
   default:
     return false;
   }
 }
 
 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,

test/Driver/openbsd.c

 // CHECK-POWERPC: as{{.*}}" "-mppc" "-many"
 // CHECK-SPARC: as{{.*}}" "-32" "-Av8"
 // CHECK-SPARC64: as{{.*}}" "-64" "-Av9"
 // CHECK-MIPS64: as{{.*}}" "-mabi" "64" "-EB"
 // CHECK-MIPS64-PIC: as{{.*}}" "-mabi" "64" "-EB" "-KPIC"
 // CHECK-MIPS64EL: as{{.*}}" "-mabi" "64" "-EL"
 // CHECK-MIPS64EL-PIC: as{{.*}}" "-mabi" "64" "-EL" "-KPIC"
 
+// Check that the integrated assembler is enabled for MIPS64
+// RUN: %clang -target mips64-unknown-openbsd -### -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-MIPS64-AS %s
+// RUN: %clang -target mips64el-unknown-openbsd -### -c %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-MIPS64-AS %s
+// CHECK-MIPS64-AS-NOT: "-no-integrated-as"
+
 // Check linking against correct startup code when (not) using PIE
 // RUN: %clang -no-canonical-prefixes -target i686-pc-openbsd %s -### 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-PIE %s
 // RUN: %clang -no-canonical-prefixes -target i686-pc-openbsd -pie %s -### 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-PIE-FLAG %s
 // RUN: %clang -no-canonical-prefixes -target i686-pc-openbsd -fno-pie %s -### 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-PIE %s
 // RUN: %clang -no-canonical-prefixes -target i686-pc-openbsd -static %s -### 2>&1 \