fix(verify): gate JIT verification to amd64 until trampolines are hardened

verify/abi_amd64.s

@@ -32,6 +32,7 @@ TEXT ·enterJITChecked(SB), NOSPLIT, $0-16
 	MOVQ fn+0(FP), AX         // target (before SP switch)
 	MOVQ SP, ·savedSP(SB)     // preserve Go stack
 	MOVQ BP, ·savedBP(SB)     // preserve frame pointer (vet requires save before clobber)
+	MOVQ R14, ·savedR14(SB)   // preserve the goroutine pointer
 	MOVQ $SENTINEL_BP, BP     // sentinel in BP
 	MOVQ $SENTINEL_R14, R14   // sentinel in R14
 	MOVQ stack+8(FP), SP      // switch to prepared stack
@@ -57,5 +58,10 @@ bp_ok:
 	ORQ  $2, ·abiResult(SB)
 
 r14_ok:
+	MOVQ ·savedR14(SB), R14   // restore the goroutine pointer: the runtime
+	                          // needs it the moment Go code resumes, whether
+	                          // or not the kernel violated it (the violation
+	                          // is already recorded in abiResult)
+	MOVQ ·savedBP(SB), BP     // restore the frame pointer
 	MOVQ ·savedSP(SB), SP
 	RET