[AutoDiff] Enable forward-mode differentiation tests.

Resolves TF-1237 TODO comments.

Author: dan-zheng

test/AutoDiff/stdlib/floating_point.swift.gyb

@@ -1,4 +1,4 @@
-// RUN: %target-run-simple-swiftgyb
+// RUN: %target-run-simple-swiftgyb(-Xfrontend -enable-experimental-forward-mode-differentiation)
 // REQUIRES: executable_test
 
 #if (arch(i386) || arch(x86_64)) && !os(Windows)
@@ -38,33 +38,24 @@ FloatingPointDerivativeTests.test("${Self}.+") {
   expectEqual((1, 1), gradient(at: ${Self}(4), ${Self}(5), in: +))
   expectEqual((10, 10), pullback(at: ${Self}(4), ${Self}(5), in: +)(${Self}(10)))
 
-  // TODO(TF-1237): Upstream forward-mode differentiation.
-  expectCrash {
-    expectEqual(2, derivative(at: ${Self}(4), ${Self}(5), in: +))
-    expectEqual(20, differential(at: ${Self}(4), ${Self}(5), in: +)(${Self}(10), ${Self}(10)))
-  }
+  expectEqual(2, derivative(at: ${Self}(4), ${Self}(5), in: +))
+  expectEqual(20, differential(at: ${Self}(4), ${Self}(5), in: +)(${Self}(10), ${Self}(10)))
 }
 
 FloatingPointDerivativeTests.test("${Self}.-") {
   expectEqual((1, -1), gradient(at: ${Self}(4), ${Self}(5), in: -))
   expectEqual((10, -10), pullback(at: ${Self}(4), ${Self}(5), in: -)(${Self}(10)))
 
-  // TODO(TF-1237): Upstream forward-mode differentiation.
-  expectCrash {
-    expectEqual(0, derivative(at: ${Self}(4), ${Self}(5), in: -))
-    expectEqual(-5, differential(at: ${Self}(4), ${Self}(5), in: -)(${Self}(5), ${Self}(10)))
-  }
+  expectEqual(0, derivative(at: ${Self}(4), ${Self}(5), in: -))
+  expectEqual(-5, differential(at: ${Self}(4), ${Self}(5), in: -)(${Self}(5), ${Self}(10)))
 }
 
 FloatingPointDerivativeTests.test("${Self}.*") {
   expectEqual((5, 4), gradient(at: ${Self}(4), ${Self}(5), in: *))
   expectEqual((50, 40), pullback(at: ${Self}(4), ${Self}(5), in: *)(${Self}(10)))
 
-  // TODO(TF-1237): Upstream forward-mode differentiation.
-  expectCrash {
-    expectEqual(9, derivative(at: ${Self}(4), ${Self}(5), in: *))
-    expectEqual(90, differential(at: ${Self}(4), ${Self}(5), in: *)(${Self}(10), ${Self}(10)))
-  }
+  expectEqual(9, derivative(at: ${Self}(4), ${Self}(5), in: *))
+  expectEqual(90, differential(at: ${Self}(4), ${Self}(5), in: *)(${Self}(10), ${Self}(10)))
 }
 
 FloatingPointDerivativeTests.test("${Self}./") {
@@ -79,11 +70,8 @@ FloatingPointDerivativeTests.test("${Self}./") {
     expectEqualWithTolerance(-1.6, dy)
   }
 
-  // TODO(TF-1237): Upstream forward-mode differentiation.
-  expectCrash {
-    expectEqualWithTolerance(0.04, derivative(at: ${Self}(4), ${Self}(5), in: /))
-    expectEqual(90, differential(at: ${Self}(4), ${Self}(5), in: *)(${Self}(10), ${Self}(10)))
-  }
+  expectEqualWithTolerance(0.04, derivative(at: ${Self}(4), ${Self}(5), in: /))
+  expectEqual(90, differential(at: ${Self}(4), ${Self}(5), in: *)(${Self}(10), ${Self}(10)))
 }
 
 FloatingPointDerivativeTests.test("${Self}.squareRoot") {

test/AutoDiff/stdlib/tgmath_derivatives.swift.gyb

@@ -1,4 +1,4 @@
-// RUN: %target-run-simple-swiftgyb
+// RUN: %target-run-simple-swiftgyb(-Xfrontend -enable-experimental-forward-mode-differentiation)
 // REQUIRES: executable_test
 
 #if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
@@ -55,10 +55,6 @@ where T == T.TangentVector {
 %for T in ['Float', 'Float80']:
 
 DerivativeTests.test("${op}_${T}") {
-%if op == 'derivative':
-  // TODO(TF-1237): Upstream forward-mode differentiation and uncomment the next line.
-  expectCrash {
-%end
   expectEqualWithTolerance(7.3890560989306502274, ${op}(at: 2 as ${T}, in: exp))
   expectEqualWithTolerance(2.772588722239781145, ${op}(at: 2 as ${T}, in: exp2))
   expectEqualWithTolerance(7.3890560989306502274, ${op}(at: 2 as ${T}, in: expm1))
@@ -86,10 +82,6 @@ DerivativeTests.test("${op}_${T}") {
   expectEqualWithTolerance(0, ${op}(at: 2 as ${T}, in: { round($0) }))
   expectEqualWithTolerance(0, ${op}(at: 2 as ${T}, in: { trunc($0) }))
 
-%if op == 'derivative':
-  } // `expectCrash` for forward-mode differentiation
-%end
-
   // Differential operator specific tests.
 
   // fma
@@ -99,10 +91,7 @@ DerivativeTests.test("${op}_${T}") {
   expectEqualWithTolerance(4, dfma.1)
   expectEqualWithTolerance(1, dfma.2)
 %else: # if op == 'derivative'
-  // TODO(TF-1237): Upstream forward-mode differentiation.
-  expectCrash {
-    expectEqualWithTolerance(10, dfma)
-  }
+  expectEqualWithTolerance(10, dfma)
 %end
 
   // remainder, fmod