[RFR] fix crash "guarantee(sect->end() <= tend) failed: sanity"

[Sergey Nazarkin]

Hi,

please review the fix for the crash caused by arch-specific patch for "8176100: [aarch32] [REDO][REDO] G1 Needs pre barrier on dereference of weak JNI handles”. 

New instruction was added to src/cpu/aarch32/vm/jniFastGetField_aarch32.cpp without code buffer expansion http://hg.openjdk.java.net/aarch32-port/jdk8u/hotspot/rev/2a07e209249a#l1.8


The patch is following
======================================================================
diff -r ff3264647a3d src/cpu/aarch32/vm/jniFastGetField_aarch32.cpp
--- a/src/cpu/aarch32/vm/jniFastGetField_aarch32.cpp    Mon Jun 03 15:12:10 2019 +0300
+++ b/src/cpu/aarch32/vm/jniFastGetField_aarch32.cpp    Fri Jun 14 19:01:27 2019 +0300
@@ -33,8 +33,8 @@

#define __ masm->

-#define BUFFER_SIZE_ARMV7 30*wordSize
-#define BUFFER_SIZE_ARMV6 50*wordSize
+#define BUFFER_SIZE_ARMV7 31*wordSize
+#define BUFFER_SIZE_ARMV6 51*wordSize

// Instead of issuing a LoadLoad barrier we create an address
// dependency between loads; this might be more efficient.
======================================================================