Bug 1235185 - Fix clang -Wclass-varargs warnings in js/. r=bhackett

js/src/jit/BacktrackingAllocator.cpp:1039:13 [-Wclass-varargs] passing object of class type 'js::jit::CodePosition' through variadic function
js/src/jit/Safepoints.cpp:168:56 [-Wclass-varargs] passing object of class type 'js::jit::SafepointSlotEntry' through variadic function
js/src/jit/Safepoints.cpp:198:57 [-Wclass-varargs] passing object of class type 'js::jit::SafepointSlotEntry' through variadic function

js/src/configure.in

@@ -1330,6 +1330,8 @@ if test "$GNU_CXX"; then
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wsign-compare"
     _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Wtype-limits"
 
+    MOZ_CXX_SUPPORTS_WARNING(-W, class-varargs, ac_cxx_has_wclass_varargs)
+
     # Treat some warnings as errors if --enable-warnings-as-errors:
     if test "$MOZ_ENABLE_WARNINGS_AS_ERRORS"; then
         _WARNINGS_CXXFLAGS="${_WARNINGS_CXXFLAGS} -Werror=char-subscripts"

js/src/jit/BacktrackingAllocator.cpp

@@ -1036,7 +1036,7 @@ BacktrackingAllocator::tryMergeReusedRegister(VirtualRegister& def, VirtualRegis
     MOZ_ASSERT(!inputRange->hasUses());
 
     JitSpew(JitSpew_RegAlloc, "  splitting reused input at %u to try to help grouping",
-            inputOf(def.ins()));
+            inputOf(def.ins()).bits());
 
     LiveBundle* firstBundle = inputRange->bundle();
     input.removeRange(inputRange);

js/src/jit/Safepoints.cpp

@@ -165,7 +165,7 @@ SafepointWriter::writeGcSlots(LSafepoint* safepoint)
 
 #ifdef JS_JITSPEW
     for (uint32_t i = 0; i < slots.length(); i++)
-        JitSpew(JitSpew_Safepoints, "    gc slot: %d", slots[i]);
+        JitSpew(JitSpew_Safepoints, "    gc slot: %u", slots[i].slot);
 #endif
 
     MapSlotsToBitset(frameSlots_, argumentSlots_, stream_, slots);
@@ -195,7 +195,7 @@ SafepointWriter::writeValueSlots(LSafepoint* safepoint)
 
 #ifdef JS_JITSPEW
     for (uint32_t i = 0; i < slots.length(); i++)
-        JitSpew(JitSpew_Safepoints, "    gc value: %d", slots[i]);
+        JitSpew(JitSpew_Safepoints, "    gc value: %u", slots[i].slot);
 #endif
 
     MapSlotsToBitset(frameSlots_, argumentSlots_, stream_, slots);