[runtime] Fixed complex.h usage in MS's thread pool to work in Android.

Android does not provide complex.h in the API levels that we compile against so bundle our own header (based on the one from FreeBSD).

Turns out GCC already provides built-in handling for the complex functions used by the code so there's no need to provide our own implementations.

mono/metadata/threadpool-microsoft.c

@@ -19,10 +19,16 @@
 //
 // Ported from C++ to C and adjusted to Mono runtime
 
+#include <config.h>
 #include <stdlib.h>
-#include <complex.h>
 #include <math.h>
 
+#ifdef PLATFORM_ANDROID
+#include <../../support/libm/complex.h>
+#else
+#include <complex.h>
+#endif
+
 #include <glib.h>
 
 #include "class-internals.h"

support/libm/complex.h

@@ -0,0 +1,118 @@
+/*-
+ * Copyright (c) 2001-2011 The FreeBSD Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _COMPLEX_H
+#define	_COMPLEX_H
+
+#include <sys/cdefs.h>
+
+#ifdef __GNUC__
+#if __STDC_VERSION__ < 199901
+#define	_Complex	__complex__
+#endif
+#define	_Complex_I	((float _Complex)1.0i)
+#endif
+
+#ifdef __generic
+_Static_assert(__generic(_Complex_I, float _Complex, 1, 0),
+    "_Complex_I must be of type float _Complex");
+#endif
+
+#define	complex		_Complex
+#define	I		_Complex_I
+
+#if __ISO_C_VISIBLE >= 2011
+#ifdef __clang__
+#define	CMPLX(x, y)	((double complex){ x, y })
+#define	CMPLXF(x, y)	((float complex){ x, y })
+#define	CMPLXL(x, y)	((long double complex){ x, y })
+#elif __GNUC_PREREQ__(4, 7)
+#define	CMPLX(x, y)	__builtin_complex((double)(x), (double)(y))
+#define	CMPLXF(x, y)	__builtin_complex((float)(x), (float)(y))
+#define	CMPLXL(x, y)	__builtin_complex((long double)(x), (long double)(y))
+#endif
+#endif /* __ISO_C_VISIBLE >= 2011 */
+
+__BEGIN_DECLS
+#pragma GCC visibility push(default)
+
+double		cabs(double complex);
+float		cabsf(float complex);
+long double	cabsl(long double complex);
+double complex	cacos(double complex);
+float complex	cacosf(float complex);
+double complex	cacosh(double complex);
+float complex	cacoshf(float complex);
+double		carg(double complex);
+float		cargf(float complex);
+long double	cargl(long double complex);
+double complex	casin(double complex);
+float complex	casinf(float complex);
+double complex	casinh(double complex);
+float complex	casinhf(float complex);
+double complex	catan(double complex);
+float complex	catanf(float complex);
+double complex	catanh(double complex);
+float complex	catanhf(float complex);
+double complex	ccos(double complex);
+float complex	ccosf(float complex);
+double complex	ccosh(double complex);
+float complex	ccoshf(float complex);
+double complex	cexp(double complex);
+float complex	cexpf(float complex);
+double		cimag(double complex) __pure2;
+float		cimagf(float complex) __pure2;
+long double	cimagl(long double complex) __pure2;
+double complex	conj(double complex) __pure2;
+float complex	conjf(float complex) __pure2;
+long double complex
+		conjl(long double complex) __pure2;
+float complex	cprojf(float complex) __pure2;
+double complex	cproj(double complex) __pure2;
+long double complex
+		cprojl(long double complex) __pure2;
+double		creal(double complex) __pure2;
+float		crealf(float complex) __pure2;
+long double	creall(long double complex) __pure2;
+double complex	csin(double complex);
+float complex	csinf(float complex);
+double complex	csinh(double complex);
+float complex	csinhf(float complex);
+double complex	csqrt(double complex);
+float complex	csqrtf(float complex);
+long double complex
+		csqrtl(long double complex);
+double complex	ctan(double complex);
+float complex	ctanf(float complex);
+double complex	ctanh(double complex);
+float complex	ctanhf(float complex);
+
+#pragma GCC visibility pop
+__END_DECLS
+
+#endif /* _COMPLEX_H */