Rename AssemblerX86 to AssemblerX8632 so it works with SZTargets.def.

This is to conditionally (ifdef) include only the enabled
target assemblers. Also rename the assembler's "x86"
namespace to "X8632" for similar reasons. The namespace was
created to hide generic sounding classes like "Address"
which are used all over the assembler.

Plop the somewhat empty AssemblerARM32 in an ARM32
namespace for consistency.

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1114223002
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index 82b0f7c..582e441 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -518,7 +518,7 @@
   Str << "(%" << getRegName(getFrameOrStackReg(), Ty) << ")";
 }
 
-x86::Address TargetX8632::stackVarToAsmOperand(const Variable *Var) const {
+X8632::Address TargetX8632::stackVarToAsmOperand(const Variable *Var) const {
   if (Var->hasReg())
     llvm_unreachable("Stack Variable has a register assigned");
   if (Var->getWeight().isInf())
@@ -526,7 +526,7 @@
   int32_t Offset = Var->getStackOffset();
   if (!hasFramePointer())
     Offset += getStackAdjustment();
-  return x86::Address(RegX8632::getEncodedGPR(getFrameOrStackReg()), Offset);
+  return X8632::Address(RegX8632::getEncodedGPR(getFrameOrStackReg()), Offset);
 }
 
 void TargetX8632::lowerArguments() {