Remove unused mips workarounds.

This was never really finished, and hasn't been supported for years.

Test: treehugger
Change-Id: I21d4c3112aa8cf0c56e59f0cc19ff8725ef714b9
diff --git a/cc/config/clang.go b/cc/config/clang.go
index d849906..274ccd5 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -49,7 +49,7 @@
 	"-Wunused-but-set-variable",
 	"-fdiagnostics-color",
 
-	// arm + arm64 + mips + mips64
+	// arm + arm64
 	"-fgcse-after-reload",
 	"-frerun-cse-after-loop",
 	"-frename-registers",
@@ -68,11 +68,6 @@
 	"-fno-tree-copy-prop",
 	"-fno-tree-loop-optimize",
 
-	// mips + mips64
-	"-msynci",
-	"-mno-synci",
-	"-mno-fused-madd",
-
 	// x86 + x86_64
 	"-finline-limit=300",
 	"-fno-inline-functions-called-once",