Bug 1473229 - Part 1: Bump minimum required ICU version to 64.1. r=jwalden

- Part 3 uses functions added in ICU 64, so we need to bump the version requirement.
- Also remove a version check which is now true be default.

Differential Revision: https://phabricator.services.mozilla.com/D26717

--HG--
extra : moz-landing-system : lando

build/autoconf/icu.m4

@@ -14,7 +14,7 @@ MOZ_ARG_WITH_BOOL(system-icu,
     MOZ_SYSTEM_ICU=1)
 
 if test -n "$MOZ_SYSTEM_ICU"; then
-    PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 63.1)
+    PKG_CHECK_MODULES(MOZ_ICU, icu-i18n >= 64.1)
     CFLAGS="$CFLAGS $MOZ_ICU_CFLAGS"
     CXXFLAGS="$CXXFLAGS $MOZ_ICU_CFLAGS"
     AC_DEFINE(MOZ_SYSTEM_ICU)

js/src/builtin/intl/ICUStubs.h

@@ -46,8 +46,6 @@
 
 #if !ENABLE_INTL_API
 
-#  define U_ICU_VERSION_MAJOR_NUM 64
-
 enum UErrorCode {
   U_ZERO_ERROR,
   U_BUFFER_OVERFLOW_ERROR,

js/src/builtin/intl/NumberFormat.cpp

@@ -496,7 +496,6 @@ static FieldType GetFieldTypeForNumberField(UNumberFormatFields fieldName,
       break;
 
 #ifndef U_HIDE_DRAFT_API
-#  if U_ICU_VERSION_MAJOR_NUM >= 64
     case UNUM_MEASURE_UNIT_FIELD:
       MOZ_ASSERT_UNREACHABLE(
           "unexpected measure unit field found, even though "
@@ -510,7 +509,6 @@ static FieldType GetFieldTypeForNumberField(UNumberFormatFields fieldName,
           "we don't use any user-defined patterns that "
           "would require a compact number notation");
       break;
-#  endif
 #endif
 
 #ifndef U_HIDE_DEPRECATED_API