[Constant] Inline ConstantInt::getSigned

ConstantInt::getSigned calls ConstantInt::get with the IsSigned flag set to true.
That flag normally defaults to false.

For always signed constants the code base is not consistent about whether
it uses ConstantInt::getSigned or ConstantInt::get with IsSigned set to true.
And it's not clear how to decide which way to use.

By making getSigned inline, both ways should generate the same code in
the end.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D146598

llvm/include/llvm/IR/Constants.h

@@ -111,8 +111,12 @@ class ConstantInt final : public ConstantData {
   /// either getSExtValue() or getZExtValue() will yield a correctly sized and
   /// signed value for the type Ty.
   /// Get a ConstantInt for a specific signed value.
-  static ConstantInt *getSigned(IntegerType *Ty, int64_t V);
-  static Constant *getSigned(Type *Ty, int64_t V);
+  static ConstantInt *getSigned(IntegerType *Ty, int64_t V) {
+    return get(Ty, V, true);
+  }
+  static Constant *getSigned(Type *Ty, int64_t V) {
+    return get(Ty, V, true);
+  }
 
   /// Return a ConstantInt with the specified value and an implied Type. The
   /// type is the integer type that corresponds to the bit width of the value.

llvm/lib/IR/Constants.cpp

@@ -899,14 +899,6 @@ ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, bool isSigned) {
   return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned));
 }
 
-ConstantInt *ConstantInt::getSigned(IntegerType *Ty, int64_t V) {
-  return get(Ty, V, true);
-}
-
-Constant *ConstantInt::getSigned(Type *Ty, int64_t V) {
-  return get(Ty, V, true);
-}
-
 Constant *ConstantInt::get(Type *Ty, const APInt& V) {
   ConstantInt *C = get(Ty->getContext(), V);
   assert(C->getType() == Ty->getScalarType() &&