tests: Move test environment header files into tests directory

Both of these headers are only used in test builds, so they should
live in tests/ directory. No changes to meson.build and
tests/meson.build files are needed because tests/meson.build adds
current directory to search for include files.

BUG=b:181803212
TEST=ninja test
-> all tests pass
nm builddir/tests/flashrom_unit_tests.p/.._it85spi.c.o
-> has symbols _test_calloc, _test_free, test_inb, test_outb
nm builddir/flashrom.p/it85spi.c.o
-> has symbols calloc free inb outb

Change-Id: Ia42773b98b1eb6c65241aa559c0c8b4926bd0814
Signed-off-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/55408
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>

tests/unittest_env.h

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright 2021 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * This header is included in all files when they are built for unit test
+ * environment, for all the files to be covered by dynamic memory allocation
+ * checks (checks for memory leaks, buffer overflows and underflows).
+ *
+ * See flashrom_test_dep in meson.build for more details.
+ *
+ * https://api.cmocka.org/group__cmocka__alloc.html
+ */
+
+extern void* _test_malloc(const size_t size, const char* file, const int line);
+extern void* _test_realloc(void *ptr, const size_t size, const char* file, const int line);
+extern void* _test_calloc(const size_t number_of_elements, const size_t size,
+                        const char* file, const int line);
+extern void _test_free(void* const ptr, const char* file, const int line);
+
+#ifdef malloc
+#undef malloc
+#endif
+#ifdef calloc
+#undef calloc
+#endif
+#ifdef realloc
+#undef realloc
+#endif
+#ifdef free
+#undef free
+#endif
+
+#define malloc(size) _test_malloc(size, __FILE__, __LINE__)
+#define realloc(ptr, size) _test_realloc(ptr, size, __FILE__, __LINE__)
+#define calloc(num, size) _test_calloc(num, size, __FILE__, __LINE__)
+#define free(ptr) _test_free(ptr, __FILE__, __LINE__)