macos: Adjust tests2.112 and tests2 Makefile

* <malloc.h> isn't as portable as <stdlib.h>
* skip 113_btdll.c on Darwin
* replace [...]\+ with [...]\{1,\} in the sed regex (basic REs
  have no + even some sed(1) accept it as \+, but bounds _are_ part
  of POSIX BREs)

tests/tests2/112_backtrace.c

@@ -84,7 +84,7 @@ int main(int argc, char **argv)
 
 /* ------------------------------------------------------- */
 #else
-#include <malloc.h>
+#include <stdlib.h>
 #include <string.h>
 char *strdup();
 int main()

tests/tests2/Makefile

@@ -14,6 +14,7 @@ ifeq ($(CONFIG_arm_eabi),yes) # not ARM soft-float
 endif
 ifdef CONFIG_OSX
  SKIP += 40_stdio.test 42_function_pointer.test
+ SKIP += 113_btdll.test # no shared lib support yet
  FLAGS += -w
  SDK := `xcrun --show-sdk-path`
  TCCFLAGS += -I$(SDK)/usr/include
@@ -88,7 +89,7 @@ GEN-ALWAYS =
 112_backtrace.test: FLAGS += -dt -b
 112_backtrace.test 113_btdll.test: FILTER += \
     -e 's;[0-9A-Fa-fx]\{5,\};........;g' \
-    -e 's;0x[0-9A-Fa-f]\+;0x?;g'
+    -e 's;0x[0-9A-Fa-f]\{1,\};0x?;g'
 
 # this test creates two DLLs and an EXE
 113_btdll.test: NORUN = true