Emit CFI for x86 & x86_64 JNI compiler.

Now for host-side x86 & x86_64 ART, we are able to get complete stacktrace with even mixed C/C++ & Java stack frames.

Testing:
1. art/test/run-test --host --gdb [--64] --no-relocate 005
2. In gdb, run 'b art::Class_classForName' which is implementation of a Java native method, then 'r'
3. In gdb, run 'bt'. You should see stack frames down to main()

Change-Id: I2d17e9aa0f6d42d374b5362a15ea35a2fce96302
diff --git a/compiler/utils/dwarf_cfi.cc b/compiler/utils/dwarf_cfi.cc
new file mode 100644
index 0000000..b3d1a47
--- /dev/null
+++ b/compiler/utils/dwarf_cfi.cc
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "leb128.h"
+#include "utils.h"
+
+#include "dwarf_cfi.h"
+
+namespace art {
+
+void DW_CFA_advance_loc(std::vector<uint8_t>* buf, uint32_t increment) {
+  if (increment < 64) {
+    // Encoding in opcode.
+    buf->push_back(0x1 << 6 | increment);
+  } else if (increment < 256) {
+    // Single byte delta.
+    buf->push_back(0x02);
+    buf->push_back(increment);
+  } else if (increment < 256 * 256) {
+    // Two byte delta.
+    buf->push_back(0x03);
+    buf->push_back(increment & 0xff);
+    buf->push_back((increment >> 8) & 0xff);
+  } else {
+    // Four byte delta.
+    buf->push_back(0x04);
+    PushWord(buf, increment);
+  }
+}
+
+void DW_CFA_offset_extended_sf(std::vector<uint8_t>* buf, int reg, int32_t offset) {
+  buf->push_back(0x11);
+  EncodeUnsignedLeb128(reg, buf);
+  EncodeSignedLeb128(offset, buf);
+}
+
+void DW_CFA_offset(std::vector<uint8_t>* buf, int reg, uint32_t offset) {
+  buf->push_back((0x2 << 6) | reg);
+  EncodeUnsignedLeb128(offset, buf);
+}
+
+void DW_CFA_def_cfa_offset(std::vector<uint8_t>* buf, int32_t offset) {
+  buf->push_back(0x0e);
+  EncodeUnsignedLeb128(offset, buf);
+}
+
+void DW_CFA_remember_state(std::vector<uint8_t>* buf) {
+  buf->push_back(0x0a);
+}
+
+void DW_CFA_restore_state(std::vector<uint8_t>* buf) {
+  buf->push_back(0x0b);
+}
+
+void WriteFDEHeader(std::vector<uint8_t>* buf) {
+  // 'length' (filled in by other functions).
+  PushWord(buf, 0);
+
+  // 'CIE_pointer' (filled in by linker).
+  PushWord(buf, 0);
+
+  // 'initial_location' (filled in by linker).
+  PushWord(buf, 0);
+
+  // 'address_range' (filled in by other functions).
+  PushWord(buf, 0);
+
+  // Augmentation length: 0
+  buf->push_back(0);
+}
+
+void WriteFDEAddressRange(std::vector<uint8_t>* buf, uint32_t data) {
+  const int kOffsetOfAddressRange = 12;
+  CHECK(buf->size() >= kOffsetOfAddressRange + sizeof(uint32_t));
+
+  uint8_t *p = buf->data() + kOffsetOfAddressRange;
+  p[0] = data;
+  p[1] = data >> 8;
+  p[2] = data >> 16;
+  p[3] = data >> 24;
+}
+
+void WriteCFILength(std::vector<uint8_t>* buf) {
+  uint32_t length = buf->size() - 4;
+  DCHECK_EQ((length & 0x3), 0U);
+  DCHECK_GT(length, 4U);
+
+  uint8_t *p = buf->data();
+  p[0] = length;
+  p[1] = length >> 8;
+  p[2] = length >> 16;
+  p[3] = length >> 24;
+}
+
+void PadCFI(std::vector<uint8_t>* buf) {
+  while (buf->size() & 0x3) {
+    buf->push_back(0);
+  }
+}
+
+}  // namespace art