cmd/compile: move over more compiler tests to new test infrastructure

R=go1.12

Update #26469

Change-Id: Iad75edfc194f8391a8ead09bfa68d446155e84ac
Reviewed-on: https://go-review.googlesource.com/127055
Run-TryBot: Keith Randall <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: David Chase <[email protected]>

Author: randall77

src/cmd/compile/internal/gc/ssa_test.go

@@ -227,19 +227,6 @@ func TestCode(t *testing.T) {
 	}
 }
 
-// TestTypeAssertion tests type assertions.
-func TestTypeAssertion(t *testing.T) { runTest(t, "assert.go") }
-
-// TestArithmetic tests that both backends have the same result for arithmetic expressions.
-func TestArithmetic(t *testing.T) { runTest(t, "arith.go") }
-
-// TestFP tests that both backends have the same result for floating point expressions.
-func TestFP(t *testing.T) { runTest(t, "fp.go") }
-
-func TestFPSoftFloat(t *testing.T) {
-	runTest(t, "fp.go", "-gcflags=-d=softfloat,ssa/check/on")
-}
-
 // TestArithmeticBoundary tests boundary results for arithmetic operations.
 func TestArithmeticBoundary(t *testing.T) { runTest(t, "arithBoundary.go") }