add cache flushing call after generating closure.

        go/test: passes 88% (306/347)

R=rsc
https://golang.org/cl/152089

Author: KaiBackman

src/pkg/runtime/arm/closure.c

@@ -43,6 +43,8 @@ vars:		WORD	arg0
 		WORD	arg2
 */
 
+extern void cacheflush(byte* start, byte* end);
+
 #pragma textflag 7
 void
 runtime·closure(int32 siz, byte *fn, byte *arg0)
@@ -121,5 +123,7 @@ runtime·closure(int32 siz, byte *fn, byte *arg0)
 
 	if(p > q)
 		throw("bad math in sys.closure");
+
+	cacheflush(*ret, q+siz);
 }
 

src/pkg/runtime/linux/arm/sys.s

@@ -22,6 +22,9 @@
 #define SYS_futex (SYS_BASE + 240)
 #define SYS_exit_group (SYS_BASE + 248)
 
+#define ARM_BASE (SYS_BASE + 0x0f0000)
+#define SYS_ARM_cacheflush (ARM_BASE + 2)
+
 TEXT write(SB),7,$0
 	MOVW	0(FP), R0
 	MOVW	4(FP), R1
@@ -136,3 +139,11 @@ TEXT clone(SB),7,$0
 	MOVW	R0, (R1)
 
 
+TEXT cacheflush(SB),7,$0
+	MOVW	0(FP), R0
+	MOVW	4(FP), R1
+	MOVW	$0, R2
+	MOVW	$SYS_ARM_cacheflush, R7
+	SWI	$0
+	RET
+