Fix riscv malloc error on small alignment after norvc.

gas/
	* config/tc-riscv.c (riscv_frag_align_code): New local insn_alignment.
	Early return if bytes less than or equal to insn_alignment.
	* testsuite/gas/riscv/align-1.l: New.
	* testsuite/gas/riscv/align-1.s: New.
	* testsuite/gas/riscv/riscv.exp: Use run_dump_tests.  Use run_list_test
	for align-1.

gas/ChangeLog

@@ -1,5 +1,12 @@
 2017-11-29  Jim Wilson  <jimw@sifive.com>
 
+	* config/tc-riscv.c (riscv_frag_align_code): New local insn_alignment.
+	Early return if bytes less than or equal to insn_alignment.
+	* testsuite/gas/riscv/align-1.l: New.
+	* testsuite/gas/riscv/align-1.s: New.
+	* testsuite/gas/riscv/riscv.exp: Use run_dump_tests.  Use run_list_test
+	for align-1.
+
 	PR gas/22464
 	* doc/c-i386.texi (-n): Clarify docs.
 

gas/config/tc-riscv.c

@@ -2319,10 +2319,18 @@ bfd_boolean
 riscv_frag_align_code (int n)
 {
   bfd_vma bytes = (bfd_vma) 1 << n;
-  bfd_vma worst_case_bytes = bytes - (riscv_opts.rvc ? 2 : 4);
+  bfd_vma insn_alignment = riscv_opts.rvc ? 2 : 4;
-  char *nops = frag_more (worst_case_bytes);
+  bfd_vma worst_case_bytes = bytes - insn_alignment;
+  char *nops;
   expressionS ex;
 
+  /* If we are moving to a smaller alignment than the instruction size, then no
+     alignment is required. */
+  if (bytes <= insn_alignment)
+    return TRUE;
+
+  nops = frag_more (worst_case_bytes);
+
   /* When not relaxing, riscv_handle_align handles code alignment.  */
   if (!riscv_opts.relax)
     return FALSE;

gas/testsuite/gas/riscv/align-1.l

@@ -0,0 +1 @@
+# No warning or error expected.

gas/testsuite/gas/riscv/align-1.s

@@ -0,0 +1,3 @@
+	.option norvc
+	.align 2
+	.align 1

gas/testsuite/gas/riscv/riscv.exp

@@ -19,13 +19,6 @@
 # MA 02110-1301, USA.
 
 if [istarget riscv*-*-*] {
-    run_dump_test "t_insns"
+    run_dump_tests [lsort [glob -nocomplain $srcdir/$subdir/*.d]]
-    run_dump_test "fmv.x"
+    run_list_test "align-1"
-    run_dump_test "c-lui-fail"
-    run_dump_test "c-addi4spn-fail"
-    run_dump_test "c-addi16sp-fail"
-    run_dump_test "satp"
-    run_dump_test "eh-relocs"
-    run_dump_test "c-lw"
-    run_dump_test "c-ld"
 }