[Driver] Default Generic_GCC x86 to -fasynchronous-unwind-tables

to match GCC and Clang's own x86-64.

Author: MaskRay

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -2713,6 +2713,7 @@ bool Generic_GCC::IsUnwindTablesDefault(const ArgList &Args) const {
   case llvm::Triple::ppcle:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
+  case llvm::Triple::x86:
   case llvm::Triple::x86_64:
     return true;
   default:

clang/test/Driver/clang-translation.c

@@ -1,10 +1,10 @@
-// RUN: %clang -target i386-unknown-unknown -### -S -O0 -Os %s -o %t.s -fverbose-asm -funwind-tables -fvisibility=hidden 2>&1 | FileCheck -check-prefix=I386 %s
+// RUN: %clang -target i386-unknown-unknown -### -S -O0 -Os %s -o %t.s -fverbose-asm -fvisibility=hidden 2>&1 | FileCheck -check-prefix=I386 %s
 // I386: "-triple" "i386-unknown-unknown"
 // I386: "-S"
 // I386: "-disable-free"
 // I386: "-mrelocation-model" "static"
 // I386: "-mframe-pointer=all"
-// I386: "-funwind-tables=1"
+// I386: "-funwind-tables=2"
 // I386: "-Os"
 // I386: "-fvisibility"
 // I386: "hidden"