[mips] Removed the SHF_ALLOC flag from the .pdr section.

Summary:
This section is used for debug information and has no need to be
in memory at runtime. With this patch, LLVM now emits the same flags as 
the GNU assembler. This patch also fixes an error when compiling 
the Linux kernel, The error is that there are relocations within the 
.pdr section in a VDSO.

Reviewers: vkalintiris, dsanders

Subscribers: llvm-commits, dsanders

Differential Revision: http://reviews.llvm.org/D17199

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260879 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp

@@ -611,7 +611,7 @@ void MipsTargetELFStreamer::emitDirectiveEnd(StringRef Name) {
   MCStreamer &OS = getStreamer();
 
   MCSectionELF *Sec = Context.getELFSection(".pdr", ELF::SHT_PROGBITS,
-                                            ELF::SHF_ALLOC | ELF::SHT_REL);
+                                            ELF::SHT_REL);
 
   MCSymbol *Sym = Context.getOrCreateSymbol(Name);
   const MCSymbolRefExpr *ExprRef =

test/MC/Mips/mips-pdr.s

@@ -18,8 +18,8 @@
 # OBJOUT: Section {
 # OBJOUT:     Name: .pdr
 # OBJOUT:     Type: SHT_PROGBITS (0x1)
-# OBJOUT:     Flags [ (0xB)
-# OBJOUT:       SHF_ALLOC (0x2)
+# OBJOUT:     Flags [ (0x9)
+# OBJOUT-NOT:   SHF_ALLOC (0x2)
 # OBJOUT:       SHF_WRITE (0x1)
 # OBJOUT:     ]
 # OBJOUT:     Size: 64