[turbofan] Float32Abs and Float64Abs are supported by all backends.

src/compiler/mips64/instruction-selector-mips64.cc

Index: src/compiler/mips64/instruction-selector-mips64.cc
diff --git a/src/compiler/mips64/instruction-selector-mips64.cc b/src/compiler/mips64/instruction-selector-mips64.cc
index 2f434954786f2bd60b27f3c9a67ecc0b09e3b970..52da27f3ac67150b0e5cde91a3c92f4e5896b4c6 100644
--- a/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/src/compiler/mips64/instruction-selector-mips64.cc
@@ -1271,9 +1271,7 @@ void InstructionSelector::VisitFloat64InsertHighWord32(Node* node) {
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
-  return MachineOperatorBuilder::kFloat32Abs |
-         MachineOperatorBuilder::kFloat64Abs |
-         MachineOperatorBuilder::kFloat64RoundDown |
+  return MachineOperatorBuilder::kFloat64RoundDown |
          MachineOperatorBuilder::kFloat64RoundTruncate;
 }