[PATCH] Makefile.global: drop -std=gnu99. C11 (or later) compiler required

[Tomi Ollila <tomi.ollila@iki.fi>]

Since October 2018 building notmuch has actually required compiler
that knows C11.

Also this -std=gnu99 was not used in code compiled by configure,
so in theory this could have caused problems...

...but no related reports have been sent, perhaps ever.

Both gcc and clang has been shipping compilers supporting C11
(or later) by default for more than four years now.

Therefore, just dropping -std=gnu99 (and not checking C11
compatibility for now, for simplicity) is easiest to do,
and removes inconsistency between configure and build time
compilations.
---
 Makefile.global | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Makefile.global b/Makefile.global
index 0aee5876..98b6962e 100644
--- a/Makefile.global
+++ b/Makefile.global
@@ -49,8 +49,7 @@ DETACHED_SIG_FILE=$(TAR_FILE).asc
 PV_FILE=bindings/python/notmuch/version.py
 
 # Smash together user's values with our extra values
-STD_CFLAGS := -std=gnu99
-FINAL_CFLAGS = -DNOTMUCH_VERSION=$(VERSION) $(CPPFLAGS) $(STD_CFLAGS) $(CFLAGS) $(WARN_CFLAGS) $(extra_cflags) $(CONFIGURE_CFLAGS)
+FINAL_CFLAGS = -DNOTMUCH_VERSION=$(VERSION) $(CPPFLAGS) $(CFLAGS) $(WARN_CFLAGS) $(extra_cflags) $(CONFIGURE_CFLAGS)
 FINAL_CXXFLAGS = $(CPPFLAGS) $(CXXFLAGS) $(WARN_CXXFLAGS) $(extra_cflags) $(extra_cxxflags) $(CONFIGURE_CXXFLAGS)
 FINAL_NOTMUCH_LDFLAGS = $(LDFLAGS) -Lutil -lnotmuch_util -Llib -lnotmuch
 ifeq ($(LIBDIR_IN_LDCONFIG),0)
-- 
2.25.1