gdbserver: rename source files to .cc

For the same reasons outlined in the previous patch, this patch renames
gdbserver source files to .cc.

I have moved the "-x c++" switch to only those rules that require it.

gdbserver/ChangeLog:

	* Makefile.in: Rename source files from .c to .cc.
	* %.c: Rename to %.cc.
	* configure.ac: Rename server.c to server.cc.
	* configure: Re-generate.

gdbserver/linux-x86-tdesc.cc

@@ -0,0 +1,164 @@
+/* GNU/Linux/x86-64 specific target description, for the remote server
+   for GDB.
+   Copyright (C) 2017-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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; either version 3 of the License, or
+   (at your option) any later version.
+
+   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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "server.h"
+#include "tdesc.h"
+#include "linux-x86-tdesc.h"
+#include "arch/i386.h"
+#include "gdbsupport/x86-xstate.h"
+#ifdef __x86_64__
+#include "arch/amd64.h"
+#endif
+#include "x86-tdesc.h"
+
+/* Return the right x86_linux_tdesc index for a given XCR0.  Return
+   X86_TDESC_LAST if can't find a match.  */
+
+static enum x86_linux_tdesc
+xcr0_to_tdesc_idx (uint64_t xcr0, bool is_x32)
+{
+  if (xcr0 & X86_XSTATE_PKRU)
+    {
+      if (is_x32)
+	{
+	  /* No x32 MPX and PKU, fall back to avx_avx512.  */
+	  return X86_TDESC_AVX_AVX512;
+	}
+      else
+	return X86_TDESC_AVX_MPX_AVX512_PKU;
+    }
+  else if (xcr0 & X86_XSTATE_AVX512)
+    return X86_TDESC_AVX_AVX512;
+  else if ((xcr0 & X86_XSTATE_AVX_MPX_MASK) == X86_XSTATE_AVX_MPX_MASK)
+    {
+      if (is_x32) /* No MPX on x32.  */
+	return X86_TDESC_AVX;
+      else
+	return X86_TDESC_AVX_MPX;
+    }
+  else if (xcr0 & X86_XSTATE_MPX)
+    {
+      if (is_x32) /* No MPX on x32.  */
+	return X86_TDESC_AVX;
+      else
+	return X86_TDESC_MPX;
+    }
+  else if (xcr0 & X86_XSTATE_AVX)
+    return X86_TDESC_AVX;
+  else if (xcr0 & X86_XSTATE_SSE)
+    return X86_TDESC_SSE;
+  else if (xcr0 & X86_XSTATE_X87)
+    return X86_TDESC_MMX;
+  else
+    return X86_TDESC_LAST;
+}
+
+#if defined __i386__ || !defined IN_PROCESS_AGENT
+
+static struct target_desc *i386_tdescs[X86_TDESC_LAST] = { };
+
+/* Return the target description according to XCR0.  */
+
+const struct target_desc *
+i386_linux_read_description (uint64_t xcr0)
+{
+  enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, false);
+
+  if (idx == X86_TDESC_LAST)
+    return NULL;
+
+  struct target_desc **tdesc = &i386_tdescs[idx];
+
+  if (*tdesc == NULL)
+    {
+      *tdesc = i386_create_target_description (xcr0, true, false);
+
+      init_target_desc (*tdesc, i386_expedite_regs);
+    }
+
+  return *tdesc;;
+}
+#endif
+
+#ifdef __x86_64__
+
+static target_desc *amd64_tdescs[X86_TDESC_LAST] = { };
+static target_desc *x32_tdescs[X86_TDESC_LAST] = { };
+
+const struct target_desc *
+amd64_linux_read_description (uint64_t xcr0, bool is_x32)
+{
+  enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, is_x32);
+
+  if (idx == X86_TDESC_LAST)
+    return NULL;
+
+  struct target_desc **tdesc = NULL;
+
+  if (is_x32)
+    tdesc = &x32_tdescs[idx];
+  else
+    tdesc = &amd64_tdescs[idx];
+
+  if (*tdesc == NULL)
+    {
+      *tdesc = amd64_create_target_description (xcr0, is_x32, true, true);
+
+      init_target_desc (*tdesc, amd64_expedite_regs);
+    }
+  return *tdesc;
+}
+
+#endif
+
+#ifndef IN_PROCESS_AGENT
+
+int
+i386_get_ipa_tdesc_idx (const struct target_desc *tdesc)
+{
+  for (int i = 0; i < X86_TDESC_LAST; i++)
+    {
+      if (tdesc == i386_tdescs[i])
+	return i;
+    }
+
+  /* If none tdesc is found, return the one with minimum features.  */
+  return X86_TDESC_MMX;
+}
+
+#if defined __x86_64__
+int
+amd64_get_ipa_tdesc_idx (const struct target_desc *tdesc)
+{
+  for (int i = 0; i < X86_TDESC_LAST; i++)
+    {
+      if (tdesc == amd64_tdescs[i])
+	return i;
+    }
+  for (int i = 0; i < X86_TDESC_LAST; i++)
+    {
+      if (tdesc == x32_tdescs[i])
+	return i;
+    }
+
+  return X86_TDESC_SSE;
+}
+
+#endif
+#endif