fold SK_CPU_HAS_CONDITION_INSTR through as always defined

src/effects/gradients/SkLinearGradient.cpp

Index: src/effects/gradients/SkLinearGradient.cpp
diff --git a/src/effects/gradients/SkLinearGradient.cpp b/src/effects/gradients/SkLinearGradient.cpp
index 4bc697d9047c425889a6900307d4b5014a9122e5..2f56cb49ca21c2b4443663a5259def64bf31f24d 100644
--- a/src/effects/gradients/SkLinearGradient.cpp
+++ b/src/effects/gradients/SkLinearGradient.cpp
@@ -23,26 +23,17 @@ static inline int repeat_8bits(int x) {
 #endif
 
 static inline int mirror_bits(int x, const int bits) {
-#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
-    if (x & (1 << bits))
+    if (x & (1 << bits)) {
         x = ~x;
+    }
     return x & ((1 << bits) - 1);
-#else
-    int s = x << (31 - bits) >> 31;
-    return (x ^ s) & ((1 << bits) - 1);
-#endif
 }
 
 static inline int mirror_8bits(int x) {
-#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
     if (x & 256) {
         x = ~x;
     }
     return x & 255;
-#else
-    int s = x << 23 >> 31;
-    return (x ^ s) & 0xFF;
-#endif
 }
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1600)