Add r228939 back with a fix.

The problem in the original patch was not switching back to .text after printing
an eh table.

Original message:

On ELF, put PIC jump tables in a non executable section.

Fixes PR22558.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229586 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -359,6 +359,13 @@ const MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable(
   return getContext().getELFSection(Name, ELF::SHT_PROGBITS, Flags, 0, Group);
 }
 
+bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection(
+    bool UsesLabelDifference, const Function &F) const {
+  // We can always create relative relocations, so use another section
+  // that can be marked non-executable.
+  return false;
+}
+
 /// getSectionForConstant - Given a mergeable constant with the
 /// specified size and relocation information, return a section that it
 /// should be placed in.