[Linux] Turn off -mstackrealign for breakpad in ia32.

There's a clang bug which causes crashes of syscalls which use many
registers for argument passing in ia32 architecture.
https://llvm.org/bugs/show_bug.cgi?id=16830

BUG=556393

Review URL: https://codereview.chromium.org/1473203002

Cr-Commit-Position: refs/heads/master@{#365770}

breakpad/BUILD.gn

@@ -554,6 +554,13 @@ if (is_linux || is_android) {
       cflags = [ "-marm" ]
     }
 
+    if (current_cpu == "x86" && is_clang) {
+      # Clang's -mstackrealign doesn't work well with
+      # linux_syscall_support.h hand written asm syscalls.
+      # See https://crbug.com/556393
+      cflags -= [ "-mstackrealign" ]
+    }
+
     if (is_android) {
       sources += [ "src/common/android/breakpad_getcontext.S" ]
     }
@@ -659,6 +666,13 @@ if (is_linux || is_android) {
       libs = [ "log" ]
       include_dirs += [ "src/common/android/include" ]
     }
+
+    if (current_cpu == "x86" && is_clang) {
+      # Clang's -mstackrealign doesn't work well with
+      # linux_syscall_support.h hand written asm syscalls.
+      # See https://crbug.com/556393
+      cflags -= [ "-mstackrealign" ]
+    }
   }
 
   executable("linux_dumper_unittest_helper") {

breakpad/breakpad.gyp

@@ -594,6 +594,14 @@
                 ],
               },
             }],
+            ['clang==1 and target_arch=="ia32"', {
+              'cflags!': [
+                # Clang's -mstackrealign doesn't work well with
+                # linux_syscall_support.h hand written asm syscalls.
+                # See https://crbug.com/556393
+                '-mstackrealign',
+              ],
+            }],
           ],
 
           'include_dirs': [
@@ -703,6 +711,14 @@
               },
               'includes': [ '../build/android/test_runner.gypi' ],
             }],
+            ['clang==1 and target_arch=="ia32"', {
+              'cflags!': [
+                # Clang's -mstackrealign doesn't work well with
+                # linux_syscall_support.h hand written asm syscalls.
+                # See https://crbug.com/556393
+                '-mstackrealign',
+              ],
+            }],
           ],
         },
         {

components/crash.gypi

@@ -158,6 +158,14 @@
                 '../breakpad/src',
               ],
             }],
+            ['clang==1 and target_arch=="ia32"', {
+              'cflags!': [
+                # Clang's -mstackrealign doesn't work well with
+                # linux_syscall_support.h hand written asm syscalls.
+                # See https://crbug.com/556393
+                '-mstackrealign',
+              ],
+            }],
           ],
           'target_conditions': [
             # Need 'target_conditions' to override default filename_rules to include

components/crash/content/app/BUILD.gn

@@ -114,6 +114,13 @@ source_set("app_non_mac_win") {
     defines += [ "CHROME_BUILD_ID=\"$android_chrome_build_id\"" ]
   }
 
+  if (current_cpu == "x86" && is_clang) {
+    # Clang's -mstackrealign doesn't work well with
+    # linux_syscall_support.h hand written asm syscalls.
+    # See https://crbug.com/556393
+    cflags -= [ "-mstackrealign" ]
+  }
+
   if (is_win) {
     deps += [
       "//breakpad:breakpad_handler",