[TextAPI] Prefix all architecture enums to fix the build on i386.

Summary: This changes the Architecture enum to use a prefix (AK_) to prevent the
preprocessor from replacing i386 with 1 when building llvm/clang for i386.

Reviewers: steven_wu, lhames, mstorsjo

Reviewed By: mstorsjo

Subscribers: hiraditya, jkorous, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60241

llvm-svn: 357733
diff --git a/llvm/lib/TextAPI/MachO/ArchitectureSet.cpp b/llvm/lib/TextAPI/MachO/ArchitectureSet.cpp
index 882305c..c589671 100644
--- a/llvm/lib/TextAPI/MachO/ArchitectureSet.cpp
+++ b/llvm/lib/TextAPI/MachO/ArchitectureSet.cpp
@@ -18,7 +18,7 @@
 ArchitectureSet::ArchitectureSet(const std::vector<Architecture> &Archs)
     : ArchitectureSet() {
   for (auto Arch : Archs) {
-    if (Arch == Architecture::unknown)
+    if (Arch == AK_unknown)
       continue;
     set(Arch);
   }
@@ -51,7 +51,7 @@
 ArchitectureSet::operator std::vector<Architecture>() const {
   std::vector<Architecture> archs;
   for (auto arch : *this) {
-    if (arch == Architecture::unknown)
+    if (arch == AK_unknown)
       continue;
     archs.emplace_back(arch);
   }