Make concrete classes for individual call descriptors.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 57a2542a36d6cea1e0585cf339a0e8c7a1ef4cbc..71b25489bec8c9876d726e1ef79c9d60e213532e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -730,7 +730,6 @@ source_set("v8_base") {
     "src/ic/ic.h",
     "src/ic/ic-compiler.cc",
     "src/ic/ic-compiler.h",
-    "src/ic/ic-conventions.h",
     "src/ic/stub-cache.cc",
     "src/ic/stub-cache.h",
     "src/interface.cc",
@@ -910,7 +909,6 @@ source_set("v8_base") {
       "src/compiler/ia32/instruction-selector-ia32.cc",
       "src/compiler/ia32/linkage-ia32.cc",
       "src/ic/ia32/ic-ia32.cc",
-      "src/ic/ia32/ic-conventions-ia32.cc",
       "src/ic/ia32/handler-ia32.cc",
       "src/ic/ia32/stub-cache-ia32.cc",
     ]
@@ -950,7 +948,6 @@ source_set("v8_base") {
       "src/ic/x64/handler-compiler-x64.cc",
       "src/ic/x64/ic-x64.cc",
       "src/ic/x64/ic-compiler-x64.cc",
-      "src/ic/x64/ic-conventions-x64.cc",
       "src/ic/x64/stub-cache-x64.cc",
     ]
   } else if (v8_target_arch == "arm") {
@@ -993,7 +990,6 @@ source_set("v8_base") {
       "src/ic/arm/handler-compiler-arm.cc",
       "src/ic/arm/ic-arm.cc",
       "src/ic/arm/ic-compiler-arm.cc",
-      "src/ic/arm/ic-conventions-arm.cc",
       "src/ic/arm/stub-cache-arm.cc",
     ]
   } else if (v8_target_arch == "arm64") {
@@ -1047,7 +1043,6 @@ source_set("v8_base") {
       "src/ic/arm64/handler-compiler-arm64.cc",
       "src/ic/arm64/ic-arm64.cc",
       "src/ic/arm64/ic-compiler-arm64.cc",
-      "src/ic/arm64/ic-conventions-arm64.cc",
       "src/ic/arm64/stub-cache-arm64.cc",
     ]
   } else if (v8_target_arch == "mipsel") {