t/Makefile: Use $(sort ...) explicitly where needed

Starting from GNU Make 3.82 $(wildcard ...) no longer sorts the result
(from NEWS):

    * WARNING: Backward-incompatibility!
      Wildcards were not documented as returning sorted values, but the results
      have been sorted up until this release..  If your makefiles require sorted
      results from wildcard expansions, use the $(sort ...)  function to request
      it explicitly.

    2a59dc32aa

I usually watch test progress visually, and if tests are sorted, even
with make -j4 they go more or less incrementally by their t number. On
the other side, without sorting, tests are executed in seemingly random
order even for -j1. Let's please maintain sane tests order for perceived
prettyness.

Another note is that in GNU Make sort also works as uniq, so after sort
being removed, we might expect e.g. $(wildcard *.sh a.*) to produce
duplicates for e.g. "a.sh". From this point of view, adding sort could
be seen as hardening t/Makefile from accidentally introduced dups.

It turned out that prevous releases of GNU Make did not perform full
sort in $(wildcard), only sorting results for each pattern, that's why
explicit sort-as-uniq is relevant even for older makes.

Signed-off-by: Kirill Smelkov <kirr@navytux.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/Makefile

@@ -17,9 +17,9 @@ DEFAULT_TEST_TARGET ?= test
 # Shell quote;
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 
-T = $(wildcard t[0-9][0-9][0-9][0-9]-*.sh)
-TSVN = $(wildcard t91[0-9][0-9]-*.sh)
-TGITWEB = $(wildcard t95[0-9][0-9]-*.sh)
+T = $(sort $(wildcard t[0-9][0-9][0-9][0-9]-*.sh))
+TSVN = $(sort $(wildcard t91[0-9][0-9]-*.sh))
+TGITWEB = $(sort $(wildcard t95[0-9][0-9]-*.sh))
 
 all: $(DEFAULT_TEST_TARGET)