Use __builtin_frame_address instead of inline assembly on non-Windows platforms.

runtime/vm/globals.h

Index: runtime/vm/globals.h
diff --git a/runtime/vm/globals.h b/runtime/vm/globals.h
index 7f72f41f5b7dfc26c0fdbffbc923b73bc759259b..f07576fcdb66579924737f92f5272f12dfc5718a 100644
--- a/runtime/vm/globals.h
+++ b/runtime/vm/globals.h
@@ -116,24 +116,9 @@ static const uword kZapUninitializedWord = 0xabababababababab;
 
 #else  // !defined(HOST_OS_WINDOWS))
 
-// Assume GCC-like inline syntax is valid.
-#if defined(HOST_ARCH_IA32)
-#define COPY_FP_REGISTER(fp) asm volatile("movl %%ebp, %0" : "=r"(fp));
-#elif defined(HOST_ARCH_X64)
-#define COPY_FP_REGISTER(fp) asm volatile("movq %%rbp, %0" : "=r"(fp));
-#elif defined(HOST_ARCH_ARM)
-#if defined(HOST_OS_MAC)
-#define COPY_FP_REGISTER(fp) asm volatile("mov %0, r7" : "=r"(fp));
-#else
-#define COPY_FP_REGISTER(fp) asm volatile("mov %0, r11" : "=r"(fp));
-#endif
-#elif defined(HOST_ARCH_ARM64)
-#define COPY_FP_REGISTER(fp) asm volatile("mov %0, x29" : "=r"(fp));
-#elif defined(HOST_ARCH_MIPS)
-#define COPY_FP_REGISTER(fp) asm volatile("move %0, $fp" : "=r"(fp));
-#else
-#error Unknown host architecture.
-#endif
+// Assume GCC-compatible builtins.
+#define COPY_FP_REGISTER(fp)                                                   \
+  fp = reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
 
 #endif  // !defined(HOST_OS_WINDOWS))