CMake: generate GameDatabaseBuiltin.cpp with cmake -P instead of sh

The gamedb custom command invoked tools/gen_gamedb_builtin.sh via sh,
which does not exist on the MSVC Windows runner (libretro-build-windows-x64,
MSB8066 / exit code 9009). Add tools/gen_gamedb_builtin.cmake, a cmake -P
twin of the shell script (file(READ HEX) + regex, no {n} quantifier or
string(REPEAT) so CMake 3.12 still works), and point the custom command at
it. Output is byte-identical to the .sh generator. The static Makefile rule
still uses the shell script and is unchanged.

pcsx2/CMakeLists.txt

@@ -1,14 +1,16 @@
 # All flags, libraries, etc, that are shared between PCSX2 compilation files
 # GameDatabaseBuiltin.cpp is generated from the shipped GameIndex.yaml at
-# build time (tools/gen_gamedb_builtin.sh, POSIX shell + od + awk only),
-# mirroring the static-Makefile rule.
+# build time. The static Makefile uses tools/gen_gamedb_builtin.sh (POSIX
+# shell + od + awk); CMake uses the byte-identical cmake -P twin so MSVC
+# runners without a shell can build too.
 add_custom_command(
 	OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/GameDatabaseBuiltin.cpp
-	COMMAND sh ${CMAKE_SOURCE_DIR}/tools/gen_gamedb_builtin.sh
-		${CMAKE_SOURCE_DIR}/bin/resources/GameIndex.yaml
-		${CMAKE_CURRENT_BINARY_DIR}/GameDatabaseBuiltin.cpp
+	COMMAND ${CMAKE_COMMAND}
+		-DYAML=${CMAKE_SOURCE_DIR}/bin/resources/GameIndex.yaml
+		-DOUT=${CMAKE_CURRENT_BINARY_DIR}/GameDatabaseBuiltin.cpp
+		-P ${CMAKE_SOURCE_DIR}/tools/gen_gamedb_builtin.cmake
 	DEPENDS ${CMAKE_SOURCE_DIR}/bin/resources/GameIndex.yaml
-	        ${CMAKE_SOURCE_DIR}/tools/gen_gamedb_builtin.sh
+	        ${CMAKE_SOURCE_DIR}/tools/gen_gamedb_builtin.cmake
 	COMMENT "Generating GameDatabaseBuiltin.cpp from GameIndex.yaml"
 	VERBATIM)
 

tools/gen_gamedb_builtin.cmake

@@ -0,0 +1,37 @@
+# Generate GameDatabaseBuiltin.cpp from bin/resources/GameIndex.yaml.
+# CMake-script twin of tools/gen_gamedb_builtin.sh for hosts without a
+# POSIX shell (MSVC runners). Output is byte-identical to the .sh script.
+# Usage: cmake -DYAML=<in> -DOUT=<out.cpp> -P gen_gamedb_builtin.cmake
+if(NOT YAML OR NOT OUT)
+	message(FATAL_ERROR "gen_gamedb_builtin.cmake: -DYAML=<in> -DOUT=<out.cpp> required")
+endif()
+file(READ "${YAML}" HEX HEX)
+# "0x..," per byte, 20 bytes per line (matches the awk layout).
+string(REGEX REPLACE "([0-9a-f][0-9a-f])" "0x\\1," HEX "${HEX}")
+# CMake regex has no {n} quantifier: spell out 20 repetitions.
+set(_LINE "")
+foreach(_i RANGE 1 20)
+	string(APPEND _LINE "0x[0-9a-f][0-9a-f],")
+endforeach()
+string(REGEX REPLACE "(${_LINE})" "\\1\n" HEX "${HEX}")
+if(NOT HEX MATCHES "\n$")
+	string(APPEND HEX "\n")
+endif()
+file(WRITE "${OUT}.tmp"
+"// Auto-generated from bin/resources/GameIndex.yaml. Do not edit by hand.
+// Generated at build time by tools/gen_gamedb_builtin.sh.
+//
+// Embeds the PCSX2 game-compatibility database into the core so it works
+// without an external <systemdir>/resources/GameIndex.yaml.
+
+#include <cstddef>
+
+extern const unsigned char g_gameDatabaseBuiltin[];
+extern const size_t g_gameDatabaseBuiltinSize;
+
+const unsigned char g_gameDatabaseBuiltin[] = {
+${HEX}};
+
+const size_t g_gameDatabaseBuiltinSize = sizeof(g_gameDatabaseBuiltin);
+")
+file(RENAME "${OUT}.tmp" "${OUT}")