[PATCH] Don't emit prologues/epilogues for naked functions (PR18791, PR20028)

[Reid Kleckner]

lgtm

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Comment at: lib/Sema/SemaStmtAsm.cpp:414
@@ +413,3 @@
+          Diag(Id.getLocStart(), diag::err_asm_naked_parm_ref);
+          Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
+        }
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thakis wrote:
> Do you need to ` Func->setInvalidDecl();` here too?
Let's do that.

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Comment at: test/CodeGen/attr-naked.c:21
@@ +20,3 @@
+// CHECK: define void @t3(i32)
+// CHECK-NEXT: entry
+// CHECK-NOT: alloca
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This CHECK will fail in a non-asserts build, because the name 'entry' will be elided. I guess I'd just rely on the CHECK-NOT for alloca and store followed by CHECK unreachable.

http://reviews.llvm.org/D5183