[PATCH RFC 2/5] fix build errors with gcc6

[Guido Trentalancia]

The following (RFC) patch aims to fix the following build error
with gcc6:

/home/guido/new/jdk8u60/mercurial-rep/jdk8u60/hotspot/src/os/linux/vm/os_linux.cpp: In static member function ‘static void* os::dll_load(const char*, char*, int)’:
/home/guido/new/jdk8u60/mercurial-rep/jdk8u60/hotspot/src/os/linux/vm/os_linux.cpp:1939:66: warning: narrowing conversion of ‘elf_head.Elf32_Ehdr::e_ident[4]’ from ‘unsigned char’ to ‘char’ inside { } [-Wnarrowing]
   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
                                         ~~~~~~~~~~~~~~~~~~~~~~~~~^
/home/guido/new/jdk8u60/mercurial-rep/jdk8u60/hotspot/src/os/linux/vm/os_linux.cpp:1939:93: warning: narrowing conversion of ‘elf_head.Elf32_Ehdr::e_ident[5]’ from ‘unsigned char’ to ‘char’ inside { } [-Wnarrowing]
   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
                                                                     ~~~~~~~~~~~~~~~~~~~~~~~~^
/home/guido/new/jdk8u60/mercurial-rep/jdk8u60/hotspot/src/os/posix/vm/os_posix.cpp: In static member function ‘static const char* os::Posix::describe_sa_flags(int, char*, size_t)’:
/home/guido/new/jdk8u60/mercurial-rep/jdk8u60/hotspot/src/os/posix/vm/os_posix.cpp:612:3: error: narrowing conversion of ‘2147483648u’ from ‘unsigned int’ to ‘int’ inside { } [-Wnarrowing]
   };
   ^

Signed-off-by: Guido Trentalancia <guido at trentalancia.net>
---
 hotspot/src/os/posix/vm/os_posix.cpp |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- jdk8u/hotspot/src/os/posix/vm/os_posix.cpp.orig	2016-05-11 00:43:47.586130518 +0200
+++ jdk8u/hotspot/src/os/posix/vm/os_posix.cpp	2016-05-11 00:29:51.359779693 +0200
@@ -594,7 +594,7 @@ const char* os::Posix::describe_sa_flags
   strncpy(buffer, "none", size);
 
   const struct {
-    int i;
+    unsigned int i;
     const char* s;
   } flaginfo [] = {
     { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
@@ -612,7 +612,7 @@ const char* os::Posix::describe_sa_flags
   };
 
   for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
-    if (flags & flaginfo[idx].i) {
+    if (((unsigned int) flags) & flaginfo[idx].i) {
       if (first) {
         jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
         first = false;