Add GDB scripts for dynamic debugging of Win32 binaries via Wine.

Ghidra/Debug/Debugger-agent-gdb/data/scripts/getpid-linux-i386.gdb

@@ -0,0 +1,22 @@
+# A GDB command to obtain the PID of a traced process, which must be running
+# on an x86 Linux host. This is primarily useful when running gdbserver.exe
+# under Wine.
+#
+# Note that binaries linked with non-executable stacks, such as those
+# created by the `-z,noexecstack` or `/NXCOMPAT` options, should replace
+# `($esp-7)` with an address that will be mapped to an executable region.
+# Selection of such an address is platform- and binary-specific.
+
+define getpid-linux-i386
+  # MOV eax,20 [SYS_getpid]
+  # INT 0x80
+  # RET
+  set $linux_getpid = {int (void)}($esp-7)
+  set {unsigned char[8]}($linux_getpid) = {\
+    0xB8, 0x14, 0x00, 0x00, 0x00, \
+    0xCD, 0x80, \
+    0xC3 \
+  }
+  output $linux_getpid()
+  echo \n
+end