fix clang 3.4 warnings and ignore uninteresting ones

fixed warnings:
src/cmd/fossil/disk.c:37:14: warning: use of GNU 'missing =' extension in designator [-Wgnu-designator]
src/cmd/fossil/disk.c:38:14: warning: use of GNU 'missing =' extension in designator [-Wgnu-designator]
src/cmd/fossil/disk.c:39:14: warning: use of GNU 'missing =' extension in designator [-Wgnu-designator]
src/cmd/fossil/disk.c:40:13: warning: use of GNU 'missing =' extension in designator [-Wgnu-designator]
src/cmd/fossil/disk.c:41:14: warning: use of GNU 'missing =' extension in designator [-Wgnu-designator]
src/libndb/ndbreorder.c:41:55: warning: for loop has empty body [-Wempty-body]

ignored warnings:
src/cmd/acid/dbg.y:393:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/bc.y:1327:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/bc.y:1327:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/grep/grep.y:420:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/grep/grep.y:420:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/hoc/hoc.y:692:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/hoc/hoc.y:692:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/lex/parser.y:886:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/rc/syn.y:303:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/cmd/units.y:1003:9: warning: array index -1 is before the beginning of the array [-Warray-bounds]
src/libregexp/regcomp.c:19:16: warning: variable 'reprog' is not needed and will not be emitted [-Wunneeded-internal-declaration]

LGTM=rsc
R=rsc
https://codereview.appspot.com/158250043

1 files changed, 2 insertions, 0 deletions

diff --git a/bin/9c b/bin/9c
index 85aa0822..64d5c3a2 100755
--- a/bin/9c
+++ b/bin/9c
@@ -67,6 +67,8 @@ useclang()
 		-Wno-unused-value \
 		-Wno-array-bounds \
 		-Wno-gnu-designator \
+		-Wno-array-bounds \
+		-Wno-unneeded-internal-declaration \
 		-fsigned-char \
 		-fno-caret-diagnostics \
 	"