Add probabability distribution utility code.

Add probabability distribution utility code that enables generation of
random deviates drawn from normal, Chi-square, and Gamma distributions.

Fix format strings in several of the assert_* macros (remove a %s).

Clean up header issues; it's critical that system headers are not
included after internal definitions potentially do things like:

  #define inline

Fix the build system to incorporate header dependencies for the test
library C files.

test/src/SFMT.c

@@ -65,9 +65,6 @@
   128-bit SIMD data type for Altivec, SSE2 or standard C
   ------------------------------------------------------*/
 #if defined(HAVE_ALTIVEC)
-  #if !defined(__APPLE__)
-    #include <altivec.h>
-  #endif
 /** 128-bit data structure */
 union W128_T {
     vector unsigned int s;
@@ -77,8 +74,6 @@ union W128_T {
 typedef union W128_T w128_t;
 
 #elif defined(HAVE_SSE2)
-  #include <emmintrin.h>
-
 /** 128-bit data structure */
 union W128_T {
     __m128i si;

test/src/math.c

@@ -0,0 +1,2 @@
+#define	MATH_C_
+#include "test/jemalloc_test.h"