SIL: Remove unnecessary isObject() assertions from ValueBuffer instructions.

SILGen is used to passing in lowered types without getting their object types specifically, and the object type may not be a legal SIL type for address-only types. Fixes rdar://problem/21408736.

Swift SVN r29436

Author: jckarter

include/swift/SIL/SILInstruction.h

@@ -390,7 +390,6 @@ class AllocValueBufferInst :
   AllocValueBufferInst(SILLocation loc, SILType valueType,
                        SILValue operand)
       : UnaryInstructionBase(loc, operand, valueType.getAddressType()) {
-    assert(valueType.isObject());
   }
 
   SILType getValueType() const { return getType().getObjectType(); }
@@ -2981,7 +2980,6 @@ class DeallocValueBufferInst :
   DeallocValueBufferInst(SILLocation loc, SILType valueType,
                          SILValue operand)
       : UnaryInstructionBase(loc, operand), ValueType(valueType) {
-    assert(valueType.isObject());
   }
 
   SILType getValueType() const { return ValueType; }
@@ -3050,7 +3048,6 @@ class ProjectValueBufferInst :
   ProjectValueBufferInst(SILLocation loc, SILType valueType,
                          SILValue operand)
       : UnaryInstructionBase(loc, operand, valueType.getAddressType()) {
-    assert(valueType.isObject());
   }
 
   SILType getValueType() const { return getType().getObjectType(); }

test/SILGen/materializeForSet.swift

@@ -145,3 +145,16 @@ struct Bill : Totalled {
 // SILGEN:   method #Totalled.total!setter.1: @_TTWV17materializeForSet4BillS_8TotalledS_FS1_s5totalSi
 // SILGEN:   method #Totalled.total!materializeForSet.1: @_TTWV17materializeForSet4BillS_8TotalledS_FS1_m5totalSi
 // SILGEN: }
+
+protocol AddressOnlySubscript {
+  typealias Index
+  subscript(i: Index) -> Index { get set }
+}
+
+struct Foo<T>: AddressOnlySubscript {
+  subscript(i: T) -> T {
+    get { return i }
+    set { print("\(i) = \(newValue)") }
+  }
+}
+