Remove internal references to "*_no_escaping_closure" semantics.

This @_semantics string is buried in the compiler but it is completely
undocumented and has no in-tree uses.

Author: atrick

lib/SILOptimizer/Analysis/EscapeAnalysis.cpp

@@ -2024,36 +2024,6 @@ void EscapeAnalysis::analyzeInstruction(SILInstruction *I,
         break;
       }
 
-    if (FAS.getReferencedFunctionOrNull() &&
-        FAS.getReferencedFunctionOrNull()->hasSemanticsAttr(
-            "self_no_escaping_closure") &&
-        ((FAS.hasIndirectSILResults() && FAS.getNumArguments() == 3) ||
-         (!FAS.hasIndirectSILResults() && FAS.getNumArguments() == 2)) &&
-        FAS.hasSelfArgument()) {
-      // The programmer has guaranteed that the closure will not capture the
-      // self pointer passed to it or anything that is transitively reachable
-      // from the pointer.
-      auto Args = FAS.getArgumentsWithoutIndirectResults();
-      // The first not indirect result argument is the closure.
-      ConGraph->setEscapesGlobal(Args[0]);
-      return;
-    }
-
-    if (FAS.getReferencedFunctionOrNull() &&
-        FAS.getReferencedFunctionOrNull()->hasSemanticsAttr(
-            "pair_no_escaping_closure") &&
-        ((FAS.hasIndirectSILResults() && FAS.getNumArguments() == 4) ||
-         (!FAS.hasIndirectSILResults() && FAS.getNumArguments() == 3)) &&
-        FAS.hasSelfArgument()) {
-      // The programmer has guaranteed that the closure will not capture the
-      // self pointer passed to it or anything that is transitively reachable
-      // from the pointer.
-      auto Args = FAS.getArgumentsWithoutIndirectResults();
-      // The second not indirect result argument is the closure.
-      ConGraph->setEscapesGlobal(Args[1]);
-      return;
-    }
-
     if (RecursionDepth < MaxRecursionDepth) {
       CalleeList Callees = BCA->getCalleeList(FAS);
       if (buildConnectionGraphForCallees(FAS.getInstruction(), Callees, FInfo,

test/SILOptimizer/escape_analysis.sil

@@ -1363,56 +1363,11 @@ sil [_semantics "array.get_element_address"] @get_element_address : $@convention
 sil [_semantics "array.get_count"] @get_count : $@convention(method) (@guaranteed Array<X>) -> Int32
 sil [_semantics "array.get_capacity"] @get_capacity : $@convention(method) (@guaranteed Array<X>) -> Int32
 
-sil [_semantics "pair_no_escaping_closure"] @unsafeWithNotEscapedSelfPointerPair : $@convention(method) (@owned X, @owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
-sil [_semantics "self_no_escaping_closure"] @unsafeWithNotEscapedSelfPointer: $@convention(method) (@owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
 sil [_semantics "array.uninitialized"] @createUninitialized : $@convention(method) (@owned AnyObject) -> (@owned Array<X>, UnsafeMutablePointer<X>)
 
 // A simplified version of swift_bufferAllocate
 sil @swift_bufferAllocate : $@convention(thin) () -> @owned AnyObject
 
-// CHECK-LABEL: CG of semantics_pair_no_escaping_closure
-// CHECK-NEXT:   Arg [ref] %0 Esc: A, Succ:
-// CHECK-NEXT:   Con [int] %0.1 Esc: A, Succ: (%0.2)
-// CHECK-NEXT:   Con [ref] %0.2 Esc: A, Succ: 
-// CHECK-NEXT:   Arg [ref] %1 Esc: A, Succ:
-// CHECK-NEXT:   Con [int] %1.1 Esc: A, Succ: (%1.2)
-// CHECK-NEXT:   Con [ref] %1.2 Esc: A, Succ: 
-// CHECK-NEXT:   Arg [ref] %2 Esc: A, Succ: (%2.1)
-// CHECK-NEXT:   Con [int] %2.1 Esc: G, Succ: (%2.2)
-// CHECK-NEXT:   Con %2.2 Esc: G, Succ: 
-// CHECK-NEXT:   Val %4 Esc: , Succ: (%4.1)
-// CHECK-NEXT:   Con [ref] %4.1 Esc: %5, Succ: 
-// CHECK-NEXT: End
-sil @semantics_pair_no_escaping_closure : $@convention(thin) (@owned X, @guaranteed X, @owned @callee_owned (X, X) -> (@out X, @error Error)) -> () {
-bb(%0 : $X, %1 : $X, %2: $@callee_owned (X, X) -> (@out X, @error Error)):
-  %3 = function_ref @unsafeWithNotEscapedSelfPointerPair : $@convention(method) (@owned X, @owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
-  %4 = alloc_stack $X
-  %6 = apply [nothrow] %3(%4, %0, %2, %1) : $@convention(method) (@owned X, @owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
-  dealloc_stack %4 : $*X
-  %7 = tuple()
-	return %7 : $()
-}
-
-// CHECK-LABEL: CG of semantics_self_no_escaping_closure
-// CHECK-NEXT:   Arg [ref] %0 Esc: A, Succ:
-// CHECK-NEXT:   Con [int] %0.1 Esc: A, Succ: (%0.2)
-// CHECK-NEXT:   Con [ref] %0.2 Esc: A, Succ: 
-// CHECK-NEXT:   Arg [ref] %1 Esc: A, Succ: (%1.1)
-// CHECK-NEXT:   Con [int] %1.1 Esc: G, Succ: (%1.2)
-// CHECK-NEXT:   Con %1.2 Esc: G, Succ: 
-// CHECK-NEXT:   Val %3 Esc: , Succ:
-// CHECK-NEXT:   Con [ref] %3.1 Esc: %4, Succ: 
-// CHECK-NEXT: End
-sil @semantics_self_no_escaping_closure : $@convention(thin) (@guaranteed X, @owned @callee_owned (X, X) -> (@out X, @error Error)) -> () {
-bb(%0 : $X, %1: $@callee_owned (X, X) -> (@out X, @error Error)):
-  %2 = function_ref @unsafeWithNotEscapedSelfPointer : $@convention(method) (@owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
-  %3 = alloc_stack $X
-  %6 = apply [nothrow] %2(%3, %1, %0) : $@convention(method) (@owned @callee_owned (X, X) -> (@out X, @error Error), @guaranteed X) -> (@out X, @error Error)
-  dealloc_stack %3 : $*X
-  %7 = tuple()
-	return %7 : $()
-}
-
 // CHECK-LABEL: CG of check_dealloc_ref
 // CHECK-NEXT:   Arg [ref] %0 Esc: A, Succ:
 // CHECK-NEXT:  End